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Abstract:

In a mask for patient ventilation, a frame portion is included for
surrounding a respiratory opening of a patient. A retention strap is
coupled with the frame portion for maintaining positive pressure between
the frame portion and the respiratory opening of the patient. A removable
insert is configured to physically attach and detach from the frame
portion without requiring removal of the frame or the retention strap
from the patient.

Claims:

1. A mask for patient ventilation comprising: a frame portion for
surrounding a respiratory opening region of a patient; a retention strap
configured to couple with the frame portion for maintaining positive
pressure between the frame portion and the respiratory opening region of
said patient; and a removable insert that is configured to physically
attach and detach from said frame portion without requiring removal of
said retention strap or said frame portion from said patient.

2. The mask of claim 1 wherein said removable insert enables access to a
nose region of said patient without requiring removal of said frame
portion.

3. The mask of claim 1 wherein said removable insert enables access to a
mouth region of said patient without requiring removal of said frame
portion.

4. The mask of claim 1 wherein said removable insert enables access to a
nose region of said patient without requiring removal of said retention
strap.

5. The mask of claim 1 wherein said removable insert enables access to a
mouth region of said patient without requiring removal of said retention
strap.

6. The mask of claim 1 further comprising: a breathing limb configured to
couple with said frame portion, said breathing limb providing fresh
respiratory gases to said patient; and wherein said breathing limb
delivers said fresh respiratory gases to said patient with said removable
insert removed from said frame portion.

7. The musk of claim 1 further comprising: a breathing limb configured to
couple with said removable insert, said breathing limb configured for
providing fresh respiratory gases to said patient when said removable
insert is coupled with said frame.

8. The mask of claim 1 wherein said removable insert includes a self
sealing port.

9. The mask of claim 1 wherein said removable insert includes a
therapeutic device.

10. The mask of claim 1 wherein said removable insert is configured to
provide a therapeutic function to said patient.

11. The mask of claim 1 wherein said removable insert is a different
color than said frame portion.

14. The mask of claim 1 wherein said removable insert comprises a
graphic.

15. A mask for patient ventilation comprising: a frame portion for
surrounding a respiratory opening region of a patient; a semi-rigid
retention strap configured for coupling with the frame portion for
maintaining positive pressure between the frame portion and the
respiratory opening region of the patient, said semi-rigid retention
strap configured to maintain a head-shape when not disposed on said
patient; and a removable insert that is configured to physically attach
and detach from said frame portion without requiring removal of said
retention strap or said frame portion from said patient.

16. The mask of claim 15 wherein said removable insert enables access to
a nose region of said patient without requiring removal of said frame
portion.

17. The mask of claim 15 wherein said removable insert enables access to
a mouth region of said patient without requiring removal of said frame
portion.

18. The mask of claim 15 wherein said removable insert enables access to
a nose region of said patient without requiring removal of said
semi-rigid retention strap.

19. The mask of claim 15 wherein said removable insert enables access to
a mouth region of said patient without requiring removal of said
semi-rigid retention strap.

20. The mask of claim 15 further comprising: a breathing limb coupled
with said frame portion, said breathing limb providing air to said
patient; and wherein said breathing limb delivers said air to said
patient with said removable insert removed from said frame portion.

21. The mask of claim 15 wherein said removable insert includes a self
sealing port.

22. The mask of claim 15 wherein said removable insert includes a
therapeutic device accessible to said patient.

23. The mask of claim 15 wherein said removable insert is configured to
provide a therapeutic function to said patient.

24. The mask of claim 15 wherein said removable insert is a different
color than said frame portion.

27. The mask of claim 15 wherein said removable insert comprises a
graphic.

28. A method for accessing a respiratory opening of a patient comprising:
ventilating said patient; accessing a frame portion of a mask surrounding
a respiratory opening region of a patient said frame portion configured
for coupling with a semi-rigid retention strap for maintaining positive
pressure between the frame portion and the respiratory opening region of
the patient; and removing a removable insert that is configured to
physically attach and detach from said frame portion without requiring
removal of said frame or said retention strap from said patient while
simultaneously ventilating said patient.

[0013] Non-invasive ventilation involves the delivery of fresh respiratory
gases to a patient through a non-invasive means such as a mask, hood, or
helmet rather than through an invasive means such as an endotracheal tube
inserted via an oral, nasal, or tracheal opening in a patient. Continuous
positive airway pressure (CPAP) ventilation and bi-level ventilation are
two specific techniques of non-invasive ventilation. CPAP ventilation, as
implied by the name, provides a continuous pressure of air during
ventilation which maintains the airway in an open state and thus can fill
the lungs with air thus requiring less work from respiratory muscles.
CPAP is often used for patients with respiratory failure or near
respiratory failure and for individuals with sleep apnea. Bi-level or
variable level ventilation is often used for sleep apnea patients and for
non-invasive ventilation for respiratory insufficiency or failure in
institutional and home setting and is similar to CPAP, except that
pressure is varied during inspiration and expiration. For example,
pressure is lowered during expiration to ease exhalation. Compared with
invasive ventilation, non-invasive ventilation can result in lower
patient stress levels and lower trauma to patient airways. As such,
non-invasive ventilation techniques offer more patient comfort than
invasive ventilation techniques.

[0014] There are three major components involved in non-invasive
ventilation: a ventilator which is an item of hardware which supplies
fresh respiratory gas(es); a patient interface such as a mask; and a
breathing circuit (i.e., tubes and connectors) that couple the ventilator
with mask such that the fresh respiratory gases can be supplied to the
patient for breathing. There are generally two techniques of non-invasive
ventilation that are commonly in use: single limb, and dual limb.

[0015] Single limb breathing circuit applications involve blowing high
flow levels of fresh respiratory gas into the patient interface, and
relying on vent ports in the patient interface for allowing exhaled
respiratory gases to exit the patient interface into the atmosphere. Vent
ports or vents are designated leakage points that allow for a controlled
leakage, or venting, of fresh respiratory gases in order to maintain a
desired pressure of respiratory gases within a patient interface and to
clear exhaled carbon dioxide. "Single limb" refers to the fact that a
ventilation limb or limbs coupled with a patient interface only supply
fresh respiratory gas and do not provide a return path for exhaled gases.
As such, in some "single limb" applications a fresh respiratory gas
supply tube may split into two or more tubes/limbs that allow fresh
respiratory gas to enter a patient interface via more than one location.
Because of the presence and reliance on vents, single limb non-invasive
ventilation is also referred to as vented non-invasive ventilation.

[0016] Dual limb breathing circuit applications involve respiratory gases
being blown into a patient interface via a first limb and exhaust gases
being evacuated from the patient interface via a second, separate limb.
Because of the second limb which is used for evacuation of exhaust gases,
no vents are needed in the patient interface for venting exhaust gases
into the atmosphere. Because no vents are required, dual limb
non-invasive ventilation is also referred to as non-vented non-invasive
ventilation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and form a
part of this application, illustrate embodiments of the subject matter,
and together with the Description of Embodiments, serve to explain the
principles of the embodiments of the subject matter. Unless noted, the
drawings referred to in this brief description of drawings should be
understood as not being drawn to scale.

[0018]FIG. 1 shows a front perspective view of an example non-invasive
ventilation system, in accordance with various embodiments.

[0019]FIG. 2 is rear perspective of a patient interface of a non-invasive
ventilation system, in accordance with various embodiments.

[0020]FIG. 3 shows a front perspective view of patient interface of a
non-invasive ventilation system and illustrates a removal/insertion of an
interchangeable patient interface insert, in accordance with an
embodiment.

[0021]FIG. 4 shows a front perspective view of patient interface of a
non-invasive ventilation system and illustrates an interchangeable
patient interface insert which includes a self-sealing access port, in
accordance with an embodiment.

[0022]FIG. 5 shows a front perspective view of patient interface of a
non-invasive ventilation system and illustrates an interchangeable
patient interface insert which includes a breath sampling port, in
accordance with an embodiment.

[0023]FIG. 6 shows a front perspective view of patient interface of a
non-invasive ventilation system and illustrates a self-sealing gastric
tube insertion region disposed within the facial skin interface, in
accordance with an embodiment.

[0024]FIG. 7 shows a front perspective view of a doffed patient interface
of a non-invasive ventilation system, in accordance with an embodiment,
and also illustrates an interchangeable patient interface insert which
includes built-in filter media, in accordance with an embodiment.

[0025] FIGS. 8A and 8B shows front perspective views of patient interfaces
of a non-invasive ventilation system which are configured with a
zygomatic facial interface and illustrate interchangeable patient
interface inserts which include an aviator style fresh respiratory gas
interface, in accordance with various embodiments.

[0026]FIG. 9 shows a method for adjusting a ventilation mask, in
accordance to an embodiment.

[0027]FIG. 10 shows a method for adjusting a ventilation mask, in
accordance to an embodiment.

[0028]FIG. 11 shows a method for assisting in opening a nasal passage, in
accordance to an embodiment.

[0029]FIG. 12 shows a front perspective view of a non-invasive patient
interface with carbon-dioxide sampling device for non-invasively
measuring carbon dioxide in exhaled breath, in accordance with an
embodiment.

[0030] FIG. 13 shows a cross-sectional view of the non-invasive patient
interface of FIG. 12 illustrating the carbon-dioxide sampling device
including a carbon dioxide collector, in accordance with an embodiment.

[0031]FIG. 14 shows a schematic diagram of a carbon-dioxide analyzer for
converting a sample of exhaled breath from the patient into a measurement
of carbon dioxide content in the sample of exhaled breath from the
patient, in accordance with an embodiment.

[0032]FIG. 15 shows a schematic diagram of an alternative embodiment for
the carbon-dioxide analyzer for converting a sensor signal form a
carbon-dioxide sensor into a measurement of carbon dioxide content in a
sample of exhaled breath from the patient, in accordance with an
embodiment.

[0033]FIG. 16 shows a flowchart of a method for non-invasively measuring
carbon dioxide in exhaled breath, in accordance with an embodiment.

[0034]FIG. 17 shows a schematic diagram of a carbon-dioxide sampling
system for accurately monitoring carbon dioxide in exhaled breath, in
accordance with an embodiment.

[0035]FIG. 18 shows a front perspective view of the non-invasive patient
interface of a combined non-invasive patient interface and carbon-dioxide
sampling system, in accordance with an embodiment.

[0036]FIG. 19 shows a schematic diagram of a carbon-dioxide analyzer
including a carbon-dioxide sensor configured to sense a level of carbon
dioxide in exhaled breath of the patient, in accordance with an
embodiment.

[0037]FIG. 20 shows a schematic diagram of a combination carbon-dioxide
measurement display and recorder, in accordance with an embodiment.

[0038]FIG. 21 shows a flowchart of a method for accurately monitoring
carbon dioxide in exhaled breath, in accordance with an embodiment.

[0039]FIG. 22 is a flow diagram of an exemplary method for accessing a
respiratory opening of a patient without removing a ventilation mask in
accordance with an embodiment.

[0040]FIG. 23 is shows a front perspective view of a doffed patient
interface of a non-invasive ventilation system with a smart component, in
accordance with an embodiment, and also illustrates a ventilator with
capability of determining system configuration, in accordance with an
embodiment.

[0041]FIG. 24 is a flow diagram of an exemplary method for determining
continuity of a ventilation system in accordance with an embodiment.

[0042]FIG. 25 is a flow diagram of an exemplary method for determining
configuration of a ventilation system in accordance with an embodiment.

[0043] FIGS. 26A-26C illustrate detail views of a self-sealing tube
insertion region, according to various embodiments.

[0044]FIG. 27 illustrates a replaceable filter cartridge, in accordance
with an embodiment.

[0045]FIG. 28 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal and a facial skin interface,
according to an embodiment.

[0046]FIG. 29 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal and a facial skin interface,
according to an embodiment.

[0047]FIG. 30 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal and a facial skin interface,
according to an embodiment.

DESCRIPTION OF EMBODIMENTS

[0048] Reference will now be made in detail to various embodiments,
examples of which are illustrated in the accompanying drawings. While the
subject matter will be described in conjunction with these embodiments,
it will be understood that they are not intended to limit the subject
matter to these embodiments. On the contrary, the subject matter
described herein is intended to cover alternatives, modifications and
equivalents, which may be included within the spirit and scope.
Furthermore, in the following description, numerous specific details are
set forth in order to provide a thorough understanding of the subject
matter. However, some embodiments may be practiced without these specific
details. In other instances, well-known structures and components have
not been described in detail as not to unnecessarily obscure aspects of
the subject matter.

Overview of Discussion

[0049] Herein, various embodiments of a non-invasive ventilation patient
interface, system, and components thereof are described. Various
embodiments described herein can be utilized across the spectrum of
non-invasive ventilation, from spontaneously breathing patients who need
some respiratory assistance to patient who are unable to breathe without
mechanical assistance. For purposes of the present description, it should
be appreciated that many of the described patient interface embodiments
may be utilized with both single limb and dual limb ventilation
applications, and may in many cases be switched over from one to another
by reconfiguring a ventilator and in some instances reconfiguring or
replacing one or more components. Description begins with a general
discussion of major components and features associated with the
non-invasive ventilation technology described herein. This general
discussion provides a framework of understanding for more particularized
description which follows in thirteen separate sections. These thirteen
sections are dedicated and focused on detailed discussion of particular
features and concepts of operation associated with one or more
embodiments of the described non-invasive ventilation technology.

Major Components and Features

[0050]FIG. 1 shows a front perspective view of an example non-invasive
ventilation system 100, in accordance with various embodiments.
Non-invasive ventilation system 100 comprises three major components,
patient interface 110 (also referred to herein as mask 110), breathing
circuit 140, and ventilator 160. Ventilator 160 supplies fresh breathable
respiratory gas such as oxygen or other repertory gas(es). Breathing
circuit 140 fluidly couples the fresh respiratory gas from ventilator 160
to patient interface 110. Patient interface 110 sealably couples in a
controlled seal (controlled in the sense that intentional leaks are
permitted while unintentional leaks are reduced or eliminated) over at
least one respiratory opening of patient 101 to form a hollow chamber
into which fresh respiratory gas is coupled via breathing circuit 140.
Although patient interface 110 is illustrated in FIG. 1 and throughout as
covering both the nasal and oral cavities (nose and mouth), some
embodiments may cover only a nasal cavity or oral cavity, or may capture
the entire face or head of a patient. Thus, in general, embodiments of
patient interface 110 can be said to couple in a controlled seal over a
respiratory opening of a patient, where a respiratory opening may include
a nasal cavity, an oral opening, both the nasal and oral cavities of a
patient, the entire face of a patient (encompassing the nasal and oral
cavities), or the entire head of a patient (encompassing the nasal and
oral cavities).

[0051] As illustrated, respiratory gas tube 141 and y-piece 142 provide a
tubular path for fluidly coupling limbs 143 and 144 of patient interface
110 with ventilator 160. In some embodiments, y-piece 142 may include one
or more swiveling portions to relieve torque and allow for articulation
of breathing circuit 140. In some embodiments, limbs 143 and 144 may both
be inhalation gas supply lines for supplying fresh respiratory gas for
breathing by patient 101. In other embodiments, one of limbs 143 or 144
acts as an inhalation gas supply line, while the other of limbs 143 and
144 acts as an exhalation gas collection line for collecting exhaust gas
(exhaled breath and unused respiratory gases) from patient 101. Although
limb 143 is illustrated herein as a single tube, it is appreciated that,
in some embodiments, limb 143 may be a plurality of smaller tubes. Such a
configuration of limb 143 facilitates the plurality of smaller tube lying
more or less flatly against and flexibly following the contour of the
face of patient 101 or of a side strap of head strap system 111.
Similarly, although limb 144 is illustrated herein as a single tube, it
is appreciated that, in some embodiments, limb 144 may be a plurality of
smaller tubes. Such a configuration of limb 144 facilitates a the
plurality of smaller tubes lying more or less flatly against and flexibly
following the contour of the face of patient 101 or of a side strap of
head strap system 111.

[0052] in one embodiment, respiratory gas tube 141 fluidly couples with
ventilator 160 via a respiratory gas port 161. All though not depicted in
FIG. 1, in some embodiments, ventilator 160 may include a plurality of
respiratory gas ports and/or other ports such as exhaled gas return
port(s) and/or a carbon dioxide monitoring port. In some embodiments,
respiratory gas port 161 and/or other connections and tubes in breathing
circuit 140 may, among other things, self-identify to ventilator 160
whether patient interface 110 is a vented or non-vented patient interface
and/or whether patient interface 110 is a neonatal, child, or adult
patient interface. Furthermore, in some embodiments, connectors and ports
of breathing circuit 140 are designed such at they only couple with
compatible components. Thus, in one embodiment, neonatal connectors would
only couple with a neonatal patient interface and a neonatal respiratory
gas port 161. In one embodiment, child connectors would only couple with
a child patient interface and a child respiratory gas port 161. In one
embodiment, adult connectors would only couple with an adult patient
interface and an adult respiratory gas port 161. These and other features
of a "smart connection" protocol will be described further herein in a
separate section below.

[0053] Anti-asphyxia valve(s) 145 (145-1, 145-2) are provided, in some
embodiments, as a safety mechanism in case the flow of fresh respiratory
gas fails or is interrupted. Anti-asphyxia valves 145 fail in an open
position to the external atmosphere, so that the anti-asphyxia valve will
open to the atmosphere to keep the patient from suffocating.

[0054] Patient interface 110 comprises a frame 125, a facial skin
interface 130, a compliant nose bridge seal 135, a domed front portion
120 (which may be fixed or may be a removable/interchangeable insert),
and a head strap system 111.

[0055] Head strap system 111 includes a plurality of side straps 112
(112-1, 112-2, and 112-3, 112-4 (not visible in FIG. 1, but illustrated
in FIG. 7)) which couple with frame 125. Upper left side strap 112-1 and
lower left side strap 112-2 couple head strap system 111 from a left
lateral portion of frame 125 around the posterior skull of patient 101
and to upper right side strap 112-3 and lower right side strap 112-4.
Upper right side strap 112-3 and lower right side strap 112-4 couple with
a right lateral portion of frame 125. Side straps 112 are adjustable such
that they may apply an adjustable securing force to secure nose bridge
seal 135 and facial skin interface 130 of patient interface in position
over one or more respiratory openings of patient 101. Adjustment of side
straps 112 facilitates adjusting the fitment and seal of facial skin
interface 130 to accommodate variety of patient facial sizes and shapes.

[0056] Side straps 112 couple with retention portions of frame 125, while
limbs 143 and 144 swivelably couple with gas ports (also referred to as
orifices) disposed as portions of frame 125. These retention portions and
gas port connection features/orifices are be better illustrated and
farther discussed in conjunction with FIG. 7.

[0057] Facial skin interface 130 is coupled with nose bridge seal 135 and
is disposed between frame 125 and the chin and cheek regions of patient
101. The general structure of facial skin interface 130 is such that
there is a flexible material in contact with the face of patient 101,
this allows for some movement of the patient while maintaining a seal
with the face of patient 101 so that respiratory gases do not
uncontrollably leak out from between facial skin interface 130 and the
facial skin of patient 101. The flexible material may be silicone, Thermo
Plastic Elastomer (TPE), two-layer or multi-layer plastic, a material of
variable wall thickness, a combination of elastic and plastic materials,
or other flexible material(s) that are known in the art. Herein flexible
means that the material is capable of flexing to conform to a surface,
such as a facial feature of a patient, in some embodiments, the flexible
material is thinner at locations where it will contact the face of a
patient and it gets more and more thick the further it gets from the
patient contact area. This increasing thickness provides some increased
rigidity and provides structure. Herein, "rigid" means that a material
does not tend to flex to conform to a surface, such as a facial feature
of a patient. While rigidity is desired in some portions of a patient
interface, lack of flexibility in regions of a patient interface which
come into contact with facial skin contributes to increased unintentional
leakage and also creates pressure points which can skin necrosis in a
relatively short period of time. Necrosis is the premature death of skin
cells and can be caused by pressure point trauma and decreased blood
circulation as a result of pressure applied to facial skin by a patient
interface. As will be further described, in some embodiments facial skin
interface 130 may incorporate one or more additional features to allow
for increased flexibility (e.g., to allow some movement and articulation
of facial skin interface 130) in order to alleviate pressure points and
improve patient comfort while still maintaining fit such that patient
ventilation is not disrupted by uncontrolled leakage of respiratory
gases. Segmented sections, corrugations, ridges, bladders, and bellows
are some examples of these additional features.

[0058] In general, the human nasal bridge has only a very thin layer of
skin covering the nasal bone structures and flexible nasal cartilage.
Because of this, the nasal bridge very susceptible to skin necrosis
caused by pressure points. Additionally, portions of the nasal passages
very easily pinch, crush, or slightly collapse in response to applied
pressure. Compliant nose bridge seal 135 couples with left and right
lateral portions of facial skin interface 130 and also couples between an
upper portion of frame 125 and the nasal bridge of patient 101. Compliant
nose bridge seal 135 is very flexible and, as such, complies with the
shape of the nasal bridge of patient 101 in response to donning of
patient interface 110. Although side straps 112 of head strap system 111
provide a securing force, the positioning of side straps 112 on frame 125
allow this securing force to be distributed via frame 125 to facial skin
interface 130. In this manner, facial skin interface 130 mostly or
entirely transfers the securing force to the chin and cheek
bone/zygomatic arch regions of the face of patient 101, while little of
none of the securing force is transferred to the nasal bridge of patient
101. Instead of relying on securing force of head strap system 111 to
form a seal, compliant nose bridge seal 135 employs one or more other
mechanisms such as corrugated sections, inflatable/inflated bladders,
medical grade foam, and/or adhesive. In some embodiments, as will be
described herein, when an adhesive, such as a hydro gel or pressure
sensitive adhesive is utilized, nose bridge seal 135 may actually be
configured to expand outward from the sides of the nose of patient 101 so
as to impart a negative or outward force on the nasal bridge region of
patient 101, while still performing a sealing function. Such an outward
force will slightly open the nasal passageways of patient 101, rather
than pinching them closed.

[0059] Domed front portion 120 is, in one embodiment, made of a
transparent material which allows a medical care professional visibility
of the oral and nasal cavities of patient 101. Domed front portion 120 is
sealably coupled with frame 125 and, in conjunction with nose bridge seal
135, facial skin interface 130, and frame 125, forms a breathing chamber
from which patient 101 may inhale fresh respiratory gas and into which
patient 101 may exhale. In vented non-invasive ventilation, domed front
portion 120 may include one or more exhaust gas vent ports 123 that allow
expulsion of exhaust gas from patient interface 110 in response to
exhalation of patient 101. In some embodiments, the size and arrangement
of vent ports 123 is selected to allow fresh respiratory gases to escape
at a predetermined flow rate in order to assist in controlling the
pressure the fresh respiratory gases near a respiratory opening (nose,
mouth, or nose and mouth) of patient 101.

[0060] As previously described, in some embodiments domed front portion
120 is a removably coupled portion of patient interface 110. In removably
coupled embodiments, domed front portion 120 may be removed from patient
interface 110 while the remainder of patient interface 110 remains in
place on patient 101. Such removal of a removable coupled domed front
portion 120 can be accomplished for a variety of reasons, including: to
facilitate oral care of patient 101, to facilitate administration of oral
or aerosolized medication to patient 101, to improve comfort of patient
101, to facilitate speech of patient 101, to clear debris (e.g., vomit,
saliva, blood, etc.) from the airway or from within patient interface
110, and facilitate insertion and/or removal of oral or nasal tubes or
medical instruments. As will be described, in some embodiments, one or
more different features may be incorporated into a domed front portion
120. In some embodiments, a domed front portion 120 may be removed and
interchangeably replaced with another domed front portion (which may
offer a feature not included in the replaced domed front portion 120). A
variety of different interchangeable versions of removable domed front
portion 120 are illustrated and described herein. Removably coupled
versions of domed front portion 120 may be referred to herein as
"interchangeable patient interface inserts," "interchangeable functional
inserts," "interchangeable inserts," "removable inserts," "inserts," or
the like.

[0061] As is described herein, in some embodiments, a domed front portion
120 may have a function or support some medical function or procedure,
and thus a domed front portion 120 may be changed out to change functions
or to facilitate performing a variety of medical functions. It is further
appreciated that, in some embodiments, domed front portions 120 may be
configured to operated with a person of a certain size (e.g., a child, an
adolescent, a grown person, an obese person, etc.). For example, vent
holes disposed in a domed front portion 120 may be configured for a
predetermined breathing rate/gas flow for a person of a particular size.
In some embodiments, a domed front portion 120 can thus be inserted into
patient interface 110 based upon the size of a patient 101 being
ventilated.

[0062]FIG. 2 is rear perspective of a patient interface 110 of a
non-invasive ventilation system 100, in accordance with various
embodiments. Limbs 143 and 144 (not visible) have been swiveled to a
forward position and hang downward toward the chest of patient 101. As
illustrated in FIG. 2, head strap system 111 defines a somewhat circular
opening 211 (it maybe perfectly circular or may be somewhere between
circular and oval in shape). It is appreciated that circular opening 211
may be devoid of material or may be covered by a fabric or other
material. Moreover, circular opening 211 may be molded and/or may be
defined by a plurality of slits made to open a region within head strap
system 111. In some embodiments, head strap system 111 is constructed
from semi-rigid material with an o-frame feature, defined by the coupling
of side straps 112-1 and 112-3 to the upper left and right lateral
portions of frame 125. This O-frame feature captures the top of the head
while circular opening 211 cradles the occipital region of the rear skull
of patient 101. The semi-rigid construction of head strap system 111
provides some amount of inherent rigidity so that when it is in storage,
it can be collapsed or folded; but when it's removed from collapsed
storage, it easily and naturally returns to a general head shaped
structure, so that it is visibly obvious how to position and install head
strap system 111 on patient 101 when donning patient interface 110. In
this manner, there is no need to sort out where the front, back, top, or
bottom is located. In one embodiment, patient interface 110 is packaged
with head strap system 111 already pre-attached with frame 125, so that
when unpackaged the semi-rigid structure of head strap system 111 causes
it to look somewhat like a helmet that can just be pulled quickly over
the head and face area of patient 101, much like putting on a catcher's
mask.

[0063] Also depicted in FIG. 2 is a quick release rip cord type pull-tab
212. The positioning of the quick release pull tab 212 may be in
different locations than illustrated and additional pull-tabs may be
included in some embodiments. As illustrated, pull-tab 212 is located
near the upper posterior skull and couples with head strap system 111.
Pull-tab 212 is easy to access and grasp by both a patient and by a
medical care professional. Pull-tab 212 provides a grasping point which
assists it doffing patient interface 110 in an expeditious fashion in
case of emergency or claustrophobia of patient 101.

[0064]FIG. 3 shows a front perspective view of patient interface 110 of a
non-invasive ventilation system 160 and illustrates removal/insertion of
an interchangeable patient interface insert 120A, in accordance with an
embodiment. As depicted, interchangeable patient interface insert 120A is
in the removed position. Interchangeable patient interface insert 120A
includes exhaust gas vent ports 123, and is thus designed for use in a
vented non-invasive ventilation application. Interchangeable patient
interface insert 120A includes one or more tabs 302 (one visible) which
correspond with, and seat into, slots 303 that are disposed in the
semi-elliptical rim 304 of frame 125. Be applying a pinching pressure on
grip regions 121-1 and 121-2 (as illustrated by arrows 301),
interchangeable patient interface insert 120A can be compressed slightly
so that tabs 302 can be seated into slots 303 and interchangeable patient
interface insert 120A can be removably coupled with frame 125. Reversal
of the installation process allows for the removal of interchangeable
patient interface insert 120A.

[0065]FIG. 4 shows a front perspective view of patient interface 110 of a
non-invasive ventilation system 100 and illustrates an interchangeable
patient interface insert 120B which includes a self-sealing access port
401, in accordance with an embodiment. Self-sealing access port 401 may
have one or more slits or openings through which a tube, such as tube 403
may be sealably inserted through interchangeable patient interface insert
120B. As depicted in FIG. 4, self-sealing access port 401 comprises one
or more slits 402. In some embodiments, as depicted, slits 402 may
intersect at right angles in the shape of a plus sign. Self-sealing
access port 401 provides an opening through which a medical professional
can perform procedures such as a bronchoscopy, as it gives access for a
bronchoscope or other tubing or medical devices/instruments which may be
inserted into the oral or nasal cavities of the patient. This allows for
insertion of tubes/devices/instruments and performance of some medical
procedures without removing patient interface 110. Instead of doffing
patient interface 110 to insert a tube or perform a procedure,
interchangeable patient interface insert 120B can be installed (if not
already installed) and the procedure can be conducted/tubing inserted
through interchangeable patient interface insert 120B. This allows
insertion of some tubing and performance of some medical procedures,
which involve oral or nasal passages, while still performing noninvasive
ventilation. For example, interchangeable patient interface insert 120B
allows for bronchoscopy to be performed on a sicker ventilated patient,
which such a procedure could not otherwise be performed on, without
removing the ventilation. Additionally, tube 403 or other
device/instrument can be left in place within self-sealing access port
401. In some embodiments, self-sealing access port 401 is sized, shaped,
and configured such that it can couple with a nebulizer, metered dose
inhaler, or other therapeutic device or drug delivery device, so that
that flow from the attached device is directed towards a mouth and/or
nose of patient 101.

[0066]FIG. 5 shows a front perspective view of patient interface 110 of a
non-invasive ventilation system 100 and illustrates an interchangeable
patient interface insert 120C which includes a breath sampling port 501,
in accordance with an embodiment. As illustrated, interchangeable patient
interface insert 120C does not include the exhaust gas vent ports that
were included on interchangeable patient interface insert 120A and
interchangeable patient interface insert 120B. In one embodiment, this
can be because exhaust gas vent ports are disposed elsewhere in patient
interface 110. In another embodiment, this is because interchangeable
patient interface insert 120C is designed for use with non-vented
non-invasive ventilation in which fresh respiratory gas for inhalation is
supplied by one limb (e.g., limb 143) and exhaust gas (exhaled breath and
unused respiratory gases) is expelled from patient interface and
collected via another limb (e.g., limb 144). Interchangeable patient
interface insert 120C includes a breath sampling port 501 to which a
breath sampling line 546 may be coupled in order to capture a sample of
exhaled breath from within patient interface 110. Breath sampling line
546 may then couple a captured exhaled breath sample to a carbon dioxide
analyzer or other analyzer.

[0067] In one embodiment, a slight concavity is defined on the interior
portion of interchangeable patient interface insert 120C(to form a breath
scoop 502. Breath scoop 502 is designed so that it is positioned in a
region roughly centered on the upper lip of patient 101 so that it can
briefly capture exhaled breath in a location where it can not be quickly
washed away by a cross-flow between limbs 143 and 144. In other
embodiments, instead of being a simple concavity defined on the interior
side of interchangeable patient interface insert 120C, breath scoop 502
may be a separate structure, coupled in approximately the same location
on the interior side of interchangeable patient interface insert 120C. In
embodiments which include breath scoop 502, breath sampling port 501
sealably couples breath sampling line 546 with breath scoop 502. Breath
sampling line 546 operates to couple a captured exhaled breath sample to
a carbon dioxide analyzer or other analyzer. Techniques for conducting
breath sampling will be discussed further in a separate section herein.

[0068]FIG. 6 shows a front perspective view of patient interface 110 of a
non-invasive ventilation system 100 and illustrates a self-sealing
gastric tube insertion region 630 disposed within or coupled with facial
skin interface 130, in accordance with an embodiment. In FIG. 6, limbs
143 and 144 are shown swiveled downward such that that drape down toward
the chest of patient 101. This swiveling allows for the fresh respiratory
gas to be provided from the front side of patient 101 instead of from the
rear/overhead of patient 101. This provides an option for patient
comfort.

[0069] As depicted in FIG. 6, a gastric tube 647 has been inserted through
a self-sealing an opening 632 defined in gastric tube insertion region
630, near the left cheek of patient 101. Gastric tube 647 may be a
venting tube, feeding tube, or the like, and may be orogastric or
nasogastric. A breath sampling tube or other tube may be inserted in a
similar manner to that of tube 647. In one embodiment, where facial skin
interface 130 includes a plurality of flexible bladder sections or
corrugations, insertion region 630 may be a gap between two of the
flexible bladders or corrugations which provides an opening 632 for
insertion of tube 647. Herein, a corrugation is a series of convolutions
that define peaks and valleys in the sealing material, and which can
flexibly expand and contract by expanding and contracting the
corrugations. Air pressure supplied by ventilator 160 may inflate the
bladders and cause them to seal about tube 647 inserted in a gap that
exists between the bladders. The bladders then transfer the securing
force (provided from head strap system 111 to frame 125) around the
inserted tube 647 such that the tube is not driven into the facial skin
of patient 101 to create a pressure point. In another embodiment, as
depicted, patient interface 110, includes an arched portion/bridge 631,
which provides a rigid or semi-rigid structure to shield tube 647 and
opening 632 from the restraining forces which are normally transferred to
facial skin interface 130 from head strap system 111, and then from
facial skin interface 130 to the facial skin of patient 101. This
prevents this restraining force from causing a pressure point by
compressing tube 647 into the skin of patient 101. In one embodiment, a
cushioning material 633, such as foam, silicone, or TPE surrounds opening
632 and provides a sealing function for self-sealing about tube 647 when
inserted in opening 632, sealing opening 632 when tube 647 is not
inserted in opening 632, and sealing to the facial skin of patient 101.

[0070] In one embodiment, all or part of insertion region 630, opening
632, cushioning material 633, and/or bridge 631 is/are configured to
breakaway facial skin interface 130. That is, one or more of these
portions may be removably coupled with facial skin interface 130. By
constructing one or more of portions 631, 632, and/or 633 such that they
may be broken away from the rest of patient interface 110, the remainder
of patient interface 110 can be removed/doffed from patient 101 without
removing tube 647 from patient 101 as would typically be required if tube
647 was inserted through some other opening in a conventional
mask/patient interface. In a similar, when tube insertion region 630 is a
gap between a pair of bladders or corrugations, tube 647 can be slipped
from between the gap and can remain inserted in patient 101 while patient
interface 110 is removed/doffed.

[0071]FIG. 7 shows a front perspective view of a doffed patient interface
110 of a non-invasive ventilation system 100, in accordance with an
embodiment, and also illustrates an interchangeable patient interface
insert 120D which includes built-in filter media 123A, in accordance with
an embodiment. FIG. 7 illustrates the manner in which the semi-rigid
structure of head strap system 111 retains the general shape of a helmet,
even in a doffed con figuration.

[0072] In one embodiment, filter media 123A can be used in conjunction
with or in place or exhaust gas vent ports 123 which have been depicted
elsewhere herein. Typically, exhaust gas vent ports 123 are open to the
atmosphere. This allows blowout of exhaled gases into the atmosphere,
which may be undesirable or even dangerous to a care giver in some
patient care circumstances. Instead of open vent holes, in one
embodiment, filter media 123A is included or alternatively utilized.
Filter media 123A provides a controlled pressure drop in addition to
filtering contagions from exhaled gases as the exhaled gases pass
through. In some embodiments, the filter media 123A can simultaneously
filter and vent, thus eliminating the need have separate vent holes.
Media such as, but not limited to, filter cloth (e.g., cotton, polyester,
or bamboo) or open cell foam may be utilized to form filter media 123A. A
variety of factors including one or more of composition, thickness,
surface area, and porosity of the media of filter media 123A can be
selected, in some embodiments, to both filter contagions and provide a
designated and intentional flow/leak rate to control internal pressure of
patient interface 110. In one embodiment, interchangeable patient
interface insert 120D can be removed and replaced with a new
interchangeable patient interface insert 120D when filter media 123A
becomes clogged, soiled, or has surpassed its recommended replacement
interval. In another embodiment, filter media 123A is, itself,
replaceable.

[0073] In the enlarged view afforded by FIG. 7, a plurality of bladders
736 are visible which are disposed in compliant nose bridge seal 135.
Bladders 736 may be filled with air, gas, or liquid upon manufacture of
patient interface 110, in one embodiment. In another embodiment, fresh
respiratory gas flow may be utilized (selectively in some embodiments),
to inflate bladders 736. Although not illustrated in FIG. 7, in some
embodiments, such bladders are also disposed around selected portions or
the entirety of the periphery of facial skin interface 130.

[0074]FIG. 7 also illustrates, fasteners 726 (726-1, 726-2, 726-3, 726-4)
to which side straps 112 (112-1, 112-2, 112-3, 112-4) may be buckled or
otherwise fastened. In some embodiments, fasteners 726 are permanently
coupled or removably coupled (i.e., snapped) into positioning tracks 727
(727-1, 727-2) along which the position of a fastener 726 may be
adjusted. When snap type fasteners 726 are utilized, unsnapping one or
more fasteners 726 provides a means for quick disconnect of side straps
112, which allows patient interface 110 to quickly doffed. Slide
adjustment allows for the positioning of fasteners 726 and helps adjust
fasteners 726 to divert securing force way from compliant nose bridge
seal 135 and the bridge of the nose of patient 101. Additionally,
positioning tracks 727 allow adjustment of the pitch and of patient
interface 110 with respect to the face of patient 101.

[0075] In some embodiments hook and loop or similar type of fastening may
be utilized to secure a side strap 112 or other component. For example,
regions 715 (715-1, 715-2, 715-3) illustrate regions where either hook
material or loop material may be disposed such that it may be mated with
its complimentary hook/loop component disposed on the end portion of a
side strap 112 or on a positioning sleeve 748 associated with a tube or
other component. When hook and loop type (or similar) fastening is
utilized to secure ends of side straps 112, a means for quickly doffing
patient interface is provided by undoing the hook and loop fastening.

[0076] In some embodiments, a side strap 112 may change colors or change
from opaque to somewhat translucent, transparent in response to a level
of force induced stress on the strap which is indicative of a level of
force or strap tightening that is considered to be so tight as to cause
necrosis if not loosened. For example, an opaque side strap 112 of any
color may stretch slightly and become translucent or transparent enough
that a color change is noticeable in response to the stress of the side
strap being stretched into an over tight state. Similarly, in some
embodiments, an opaque side strap 112 of any color may stretch slightly
and become translucent or transparent enough that that an embedded
colored thread (e.g., a red thread) becomes visibly exposed in response
to the stress of the side strap being stretched into an over tight state.
An example of such an embedded colored thread 712 is shown FIG. 7 as
being visible on the rear (patient facing) side of side strap 112-4 at
all times. In various embodiments, embedded thread 712 would only become
visibly exposed on the opposite, non-patient facing side of side strap
712-4 in response to over tightening of side strap 112-4. It is
appreciated that some or all of side straps 112 may include such a color
changing and/or embedded thread feature to indicate over tightened
conditions. In some embodiments, embedded thread 712 may be embedded such
that it is not visible at all, even on the non-patient facing side of a
side strap 712, until the side strap 712 becomes stretched into an over
tightened state.

[0077] Orifices 722 (722-1, 722-2) are openings disposed, in one
embodiment, in frame 125. Limb 143 is illustrated as being sealably
coupled with respiratory gas delivery orifice 722-1 which provides an
entry port for fresh respiratory gas from ventilator 160. Similarly, limb
144 is illustrated as being sealably coupled with respiratory gas
delivery orifice 722-2 which provides a second entry port for fresh
respiratory gas from ventilator 160 in a vented configuration. In a
non-vented configuration, limb 143 or 144 may be used to transport
exhaust gases away from patient interface 110. In such a non-vented
embodiment, orifice 722-2 may then comprise an exhaust gas orifice.

[0078] FIG. 8A shows a front perspective view of a patient interface 110A
of a non-invasive ventilation system 100 configured with a zygomatic
facial interface 831 and illustrating an interchangeable patient
interface insert 120E which includes an aviator style fresh respiratory
gas interface 822, in accordance with an embodiment. By aviator style,
what is meant is that the fresh respiratory gases enter the patient
interface at approximately a midline position on the front of the patient
interface rather than from one or both lateral sides of the patient
interface.

[0080] The zygomatic arch is a bony structure, but it also typically has a
thicker layer of fatty tissue than the bridge of the nose, which is
generally thin-skinned and has little in the way of cushioning. Because
of the thin-skin on the bridge of the nose pressure points on the bridge
of the nose quickly disrupt blood flow and create necrosis. Zygomatic
facial interface 831 provides wing like extensions (831-1 and 831-2) of
facial skin interface 130 which transfer securing forces of patient
interface 110 to the zygomatic arch areas (cheek bones) of patient 101
and also spread the securing forces over a larger surface area of facial
skin that other facial skin interfaces illustrated herein. By spreading
securing forces to the zygomatic arch, over a larger facial skin surface
area, and away from the bridge of the nose, zygomatic facial interface
831 further reduces the securing force (if any) which is transferred to
nose bridge seal 135. Zygomatic facial interface 831 spreads securing
forces over a larger surface area of facial skin, and onto zygomatic arch
structure. In one embodiment, either or both of facial skin interface 130
and zygomatic facial interface 831 may incorporate a plurality of
structural features such as corrugations, ridges, or bladders 836. One of
the major differences between a corrugation/ridge and a bladder is
internal, as a bladder may be adjustably filled with a gas or fluid,
while a corrugation/ridge cannot. Even though designed to be inflatable
filled, a bladder may still have a bumpy exterior appearance which makes
it look similar to and in some respects function similar to a
corrugation/ridge. In one embodiment, bladders 836 are similar in
structure and function to bladders 736 and provide cushioning and allow
for some flexibility and movement of patient interface 110A while still
maintaining an intact facial seal with patient 101.

[0081] In one embodiment, patient interface 110A also includes an extended
chin portion 832. Oral-nasal masks are intended to capture both the mouth
and nose. Extended chin portion 832 helps keep the patient's mouth closed
in an oral mask or an oral-nasal mask. This can increase patient comfort.
In one embodiment, extended chin portion 832 may include a bellows
feature (not visible) that expands/contracts in response to movement of
the chin of patient 101. This allows patient 101 to slightly open his/her
mouth or extend his/her chin without compromising the seal of patient
interface 110A and allowing respiratory gas to uncontrollably leak.

[0082] In FIG. 8A, side straps such as 112-2 couple with fasteners such as
fastener 826. As depicted, fastener 826 is permanently or removably
coupled into a track 827 along which it may be positioned.
Slide-to-release mechanism 828 is utilized to lock fastener 826 in a
desired position within track 827 or to unlock fastener 826 so that it
may be slidably positioned in track 827. It is noted that in FIGS. 7 and
8, strap positioning features are located near the face of patient 101 so
that they are easily accessible for adjustment by patient 101 or by a
care giver.

[0083] Although zygomatic facial interface 831, extended chin portion 832,
slide-to release-mechanism 828, and interchangeable patient interface
insert 120E are illustrated together in FIG. 8A, these features may be
utilized separately. For example, zygomatic facial interface 831 can be
incorporated into patient interface 110 which is illustrated in FIGS.
1-7. Similarly, an aviator style fresh respiratory gas interface 822 may
be utilized in patient interface 110A which does not include zygomatic
facial interface 831.

[0084] FIG. 8B is an aviator style patient interface similar to FIG. 8A in
all regards (wherein like numerals refer to like components) except that
an interchangeable patient interface insert 120F with an aviator style
fresh respiratory gas interface 822B has replaced interchangeable patient
interface insert 120E and aviator style fresh respiratory gas interface
822. As can be seen patient interface 120F includes anti-asphyxia valve
845B. As illustrated in FIG. 8B, aviator style fresh respiratory gas
interface 822 utilizes an alternative breathing circuit 840B which
comprises a ribbed respiratory gas supply tube 841 that connects directly
gas interface 822B without the use of an elbow, and which, in some
embodiments, does not include a swivel connector piece.

[0086] In various embodiments, mask 110 is adjusted by fluidly adjusting
the bladders (e.g., bladders 736 and 836). In particular, mask 110 is
adjusted by inflating the bladders by gas, air, or liquid or any
combination thereof. Also, mask 110 is adjusted by deflating the
bladders.

[0087] In one embodiment, the bladders are fluidly connected to ventilator
160. For example, each bladder is fluidly connected to ventilator 160 via
a tube. The tube may be similar to line 546 or tube 647. In such an
embodiment, each bladder is fluidly separate from one another and each
bladder is fluidly connected to ventilator 160.

[0088] Alternatively, two or more bladders (e.g., adjacent bladders or
non-adjacent bladders) may be fluidly connected to one another. As such,
the fluidly connected bladders are fluidly separate from other bladders
or other fluidly connected bladders.

[0089] In another embodiment, the bladders are fluidly connected to an
inflation source. Such as, but not limited to, a pressure tank.

[0090] Mask 110 may be adjusted for a variety of reasons. For example,
mask 110 may be adjusted in response to a detected unintentional leak.

[0091]FIG. 9 depicts an embodiment of a method 900 for adjusting a
ventilation mask.

[0092] At 910 of method 900, a ventilative state of mask 110 is measured.
It is understood that mask 110 is placed over a nose and/or mouth of a
patient, wherein a sealing portion of mask 110 is for establishing a
fluid seal between mask 110 and the patient, and wherein the sealing
portion comprises a plurality of bladders.

[0093] It is also understood that "ventilative state," used herein, is any
state of system 100 that is measurable and facilitates in determining
whether or not there is an unintentional leak between mask 110 and
patient 101. For example, a ventilative state can be, but is not limited
to, pressure, airflow, etc.

[0094] In one embodiment, at 912, airflow is measured. In another
embodiment, at 914, pressure is measured.

[0095] In various examples, ventilative states (e.g., airflow, pressure)
of non-invasive ventilation system 100 are measured. The ventilative
states can be measured by ventilator 160 or other measuring devices.

[0096] The measuring can occur by obtaining information of ventilative
states at various locations within system 100. For example, ventilative
states can be measured at mask 110, at breathing circuit 140 and/or
ventilator 160.

[0097] At 920, an unintentional leak of the fluid seal is determined based
on a measured change of the ventilative state. For example, if the
measured pressure and/or airflow in system 100 falls outside of a
prescribed or expected range, then it is determined that there is an
unintentional leak of the fluid seal. An unintentional leak between mask
110 and patient 101 may occur due to a variety of reasons (e.g., patient
may accidentally bump mask 110, patient 101 may move mask 110, etc.). As
a result, a ventilative state of system 100 may change.

[0098] At 930, a bladder is adjusted to seal the unintentional leak. For
example, at least one bladder (e.g., at least one of bladders 736 or 836)
is adjusted. In particular, if there is a gap (e.g., unintentional leak)
between a bladder and patient 101, then the bladder can be adjusted
(e.g., inflated) to seal the gap.

[0099] In one embodiment, at 931, a bladder is automatically adjusted to
seal the unintentional leak. For instance, in response to measured change
in the ventilative state (e.g., lower pressure) which is indicative of an
unintentional leak between mask 110 and patient 101, a bladder is
automatically inflated (e.g., by ventilator 160) to facilitate in sealing
the unintentional leak. Alternatively, a bladder is manually adjusted.

[0100] In another embodiment, at 932, bladders are sequentially adjusted.
For example, in response to a measured change in the ventilative state
outside an expected or prescribed range, a first bladder is inflated. If
the ventilative state still remains outside and expected or prescribed
range, another bladder is inflated, such as an adjacent bladder to the
first bladder, and so on, until the ventilate state returns to the
expected range and thus the unintentional leak is sealed. Alternatively,
a bladder inflated subsequent the first inflated bladder, is not adjacent
to the first bladder.

[0101] In a further embodiment, at 933, bladders are automatically
adjusted according to a pre-defined pattern. For example, the inflation
of bladders can initiate at an arbitrary first bladder and continue
clockwise or counterclockwise from the first bladder, until the
unintentional leak is sealed. In another example, a first bladder,
located at a position with a highest probability of unintentional
leakage, is initially automatically adjusted. A second bladder, located
at a position with a second highest probability of unintentional leakage,
is subsequently adjusted, and so on, until the unintentional leak is
sealed.

[0102] In another embodiment, at 934, a bladder is adjusted such that a
measured ventilative state returns to a prescribed ventilative state. For
example, in response to a ventilative state falling out of a prescribed
or expected range, a bladder is adjusted to stop the unintentional leak.
As a result of adjusting the bladder, the ventilative state returns to a
prescribed ventilative state in a prescribed ventilative state range
which is indicative of a proper seal between mask 110 and patient 101.

[0103] In one embodiment, at 935, more than one bladder is simultaneously
adjusted. For example, all of the bladders disposed in compliant nose
bridge seal 135 are simultaneously adjusted. In another embodiment, all
of the bladders disposed on pressure points of patient 101 are
simultaneously adjusted.

[0104] Moreover, mask 110 may be adjusted to decrease necrosis.

[0105]FIG. 10 depicts an embodiment of a method 1000 for adjusting a
ventilation mask to decrease necrosis.

[0106] At 1010 of method 1000, mask 110 is fluidly sealed to a patient
101, wherein the mask comprises a plurality of bladders (e.g., bladders
736 and 836) in physical contact with the patient.

[0107] At 1020, a bladder is adjusted to decrease necrosis. For example, a
bladder(s) is adjusted to decrease pressure at a pressure point. It
should be appreciated that a bladder(s) can be adjusted to decrease
necrosis similarly to bladders being adjusted as described in method 900.

[0108] In one embodiment, at 1022, a bladder is adjusted (e.g., deflated)
to decrease pressure on a pressure point of the patient.

[0109] In another embodiment, at 1024, inflate a bladder of the plurality
of bladders to decrease necrosis. For example, bladders surrounding a
pressure point are inflated to decrease necrosis.

[0110] In a further embodiment, at 1026, a bladder is deflated to decrease
necrosis. For example, a bladder disposed on a pressure point is deflated
to decrease necrosis.

[0111] In one embodiment, at 1028, a bladder(s) is automatically adjusted
to decrease necrosis. For example, after a predetermined amount of time,
a bladder(s) located on or about a pressure point are automatically
adjusted to decrease necrosis.

Section 2

Corrugated Flexible Seal of a Ventilation Mask

[0112] Mask 110 includes a sealing portion (e.g., compliant nose bridge
seal 135 and/or facial skin interface 130). In various embodiments, the
sealing portion is a corrugated flexible seal. For example, the sealing
portion includes bladders 736 and 836 (also referred to as corrugations
or ridges). The ridges are disposed along the corrugated flexible seal
and configured for physical contact with patient 101.

[0113] In general, the corrugated flexible seal (in particular, the ridges
of the corrugated flexible seal) allows for some flexibility and movement
of patient interface 110 while still maintaining an intact facial seal
with patient 101.

[0114] In one embodiment, corrugated flexible seal is configured to
establish a fluid seal over the nose of patient 101. For example, a fluid
seal occurs between ridges 736 of compliant nose bridge seal 135 and the
nose bridge of patient 101 (see FIG. 7). With respect to ridges 736,
their length, depth, and width (frequency) may vary in some portions of
the compliant nose bridge.

[0115] In another embodiment, the corrugated flexible seal is configured
to establish a fluid seal around the nose and/or mouth of patient 101.
For example, a fluid seal occurs around the nose and/or mouth of patient
101 by ridges 736 of compliant nose bridge seal 135 and ridges 836 of
facial skin interface 130.

[0116] Corrugated flexible seal (in particular, ridges 736 and/or ridges
836) is configured to move or flex in a plurality of axes and/or
directions. This allows for flexibility and movement of patient interface
110 while still maintaining an intact facial seal.

[0117] Ridges 736, as depicted in FIG. 7, extend along the width of
compliant nose bridge seal 135. In other words, the length of each ridge
extends in a direction from the tip of the nose towards the eyes of
patient 101. Moreover, ridges 736 are disposed along the length of nose
bridge seal 135.

[0118] Ridges 836, as depicted in FIG. 8, extend along the width of facial
skin interface 130. Moreover, ridges 836 are disposed along the length of
facial skin interface 130 (and zygomatic facial interface 831). With
respect to ridges 836, their length, depth, and width (frequency) may
vary in some portions of facial skin interface 130 and or zygomatic
facial skin interface 831. Also, in some embodiments, the length of
ridges 736 is longer than the length of ridges 836.

[0119] In various embodiments, the ridges of the corrugated flexible seal
have different shapes. For example, ridges 836 can have different shapes
from one another and/or have different shapes than ridges 736. Elsewhere
herein, microgrooves are described. It should be appreciated that ridges
and valleys of corrugations are much larger in depth and width than
microgrooves. For example, in some embodiments corrugations are at least
an order of magnitude larger than microgrooves. It is appreciated that
one or more microgrooves may be configured into a corrugation, in some
embodiments.

Section 3

Nasal Passage Opener of a Ventilation Mask

[0120] In various embodiments, mask 110 includes a nasal passage opener.
The nasal passage opener is configured for facilitating in opening of a
nasal passage (or nasal valve). The nasal passage opener is disposed over
a nasal passage (or nasal valve) of patient 101 when mask 110 is sealed
on the face of patient 101. Opening up the nasal passages (valves) can
assist in decreasing the rate of breathing and/or patient effort in
breathing.

[0121] In one embodiment, the nasal passage opener is compliant nose
bridge seal 135. For example, when compliant nose bridge seal 135 is
placed over the nasal passage, the shape of compliant nose bridge seal
135 assists in opening the nasal passage, such as with an outward
springing force which pulls open the nasal passages. As a result, the
nasal passage is assisted in opening.

[0122] In another embodiment, patient interface 110 interacts with and
slightly laterally stretches the cheek skin of patient 101, where the
cheek skin is the skin starting at the lateral edges of the nose and
extending laterally as far as the skin above the zygomatic arches. This
lateral stretching of the cheek skin pulls the nasal passages slightly
laterally to a more open state. With reference to FIGS. 1 and 3-7, in
some embodiments, the positioning of side straps 112-1 and 112-3 assists
in providing lateral pressure to facial skin interface 130 to effect the
lateral stretching of the cheek skin. With reference to FIG. 5A,
zygomatic facial interface portions 831-1 and 831-2 and the positioning
of side straps 112-1 and 112-3, in some embodiments, act in concert to
slightly laterally stretch the cheek skin of patient 101. It should be
appreciated that this cheek skin stretching operates in a similar fashion
to the Cottle test, which is used to evaluate nasal valve stenosis. As a
result of bilateral facial skin stretching the nasal passage is assisted
in opening.

[0123] In another embodiment, the nasal passage opener is a fluidly
adjustable bladder or bladders (e.g., bladders 736), as described in
Section 1. For example, bladders 736 are inflated at the nasal passage.
The inflation provides force onto portions of the nasal passage, which
may pull the nasal passage into a more open state, such as by adhesively
pulling the nasal passages open in certain regions and/or laterally
stretching cheek skin of a patient. As a result, the nasal passage is
assisted in opening.

[0124] In some embodiments, one or more of facial cheek skin stretching
may be utilized, a compliant nose bridge seal, and inflatable bladders
may be used in combination for opening the nasal passages of patient 101.

[0125] In one embodiment, the nasal passage opener is integrated with mask
110. Alternatively, the nasal passage opener is removable from mask 110.

[0126]FIG. 11 depicts an embodiment of a method for assisting in opening
a nasal passage.

[0127] At 1110, a ventilation mask is sealed over a face of a patient,
wherein the ventilation mask is disposed over a nasal passage. For
example, mask 110 is sealed over the face of patient 101, wherein mask
110 is disposed over a nasal passage.

[0128] At 1120, nasal passage is assisted in opening by the ventilation
mask disposed over the nasal passage. For example, the nasal passage is
assisted in opening by compliant nose bridge seal disposed over the nasal
passage and/or by lateral cheek skin stretching provided by mask 110.

[0129] In one embodiment, at 1122, a cross-sectional area of a nasal
passage is increased. For example, the cross-sectional area of the nasal
passage is increased because of the nasal passage opener.

[0130] In another embodiment, at 1124, a bladder is adjusted to assist in
opening of the nasal passage. For example, a single bladder is inflated
to urge in the opening of a nasal passage.

[0131] In a further embodiment, at 1126, a plurality of bladders is
adjusted to assist in opening of the nasal passage. For example, a
plurality of bladders (e.g., bladders 736) are inflated, such that it
urges open the nasal passage. As a result, the cross-sectional area of
the nasal passage is increased.

[0132] With reference now to FIG. 12, in accordance with an embodiment, a
front perspective view 1200 is shown of a non-invasive ventilation
patient interface 110, which is also referred to herein as a mask 110,
with carbon-dioxide sampling device 1201 for non-invasively measuring
carbon dioxide in exhaled breath. Patient interface 110 includes a
carbon-dioxide sampling device 1201, straps 112-1, 112-2 and 112-3, an
inhalation gas supply line 144, which is also referred to herein as limb
144 of the breathing circuit 140, and an exhalation gas collection line
143, which is also referred to herein as limb 143 of the breathing
circuit 140. The inhalation gas supply line may be identified with limb
144 of the breathing circuit 140, as previously described; and, the
exhalation gas collection line may be identified with limb 143 of the
breathing circuit 140, as previously described; however, these
identifications of the inhalation gas supply line and the exhalation gas
collection line are by way of example, without limitation thereto, as
other implementations of the inhalation gas supply line and the
exhalation gas collection line are within the spirit and scope of
embodiments described herein. In addition, patient interface 110 may also
include a y-piece 142, as previously described, which functions as a
gas-line coupling.

[0133] With further reference to FIG. 12, in accordance with an
embodiment, the carbon-dioxide sampling device 1201 is configured to
non-invasively measure carbon dioxide in exhaled breath. The
carbon-dioxide sampling device 1201 includes a breath-sampling chamber
1210, and a carbon-dioxide collector 502, which is also referred to
herein as breath scoop 502. The carbon-dioxide collector 502 may be
identified with the breath scoop 502, as previously described; however,
this identification of the carbon-dioxide collector 502 is by way of
example, without limitation thereto, as other implementations of the
carbon-dioxide collector 502 are within the spirit and scope of
embodiments described herein. The breath-sampling chamber 1210 is
configured to be disposed over a patient's mouth and/or nose, and
configured to seal with a patient's face preventing unintentional leakage
of respiratory gases from the breath-sampling chamber 1210. By way of
example without limitation thereto, the breath sampling chamber 1210
includes a frame 125, a facial skin interface 130, a compliant nose
bridge seal 135, and an interchangeable patient interface insert 120C,
which have been previously described. The carbon-dioxide collector 502 is
disposed in the breath-sampling chamber 1210. The carbon-dioxide
collector 502 is configured to be disposed in proximity to, and outside
of, the nose and/or mouth of the patient 101, and to collect a sample of
exhaled breath from the patient 101. The straps 112-1, 112-2 and 112-3
are configured to hold the breath-sampling chamber 1210 in place over the
patient's mouth and/or nose, and to apply tension to make a seal with a
patient's face preventing unintentional leakage of respiratory gases from
the breath-sampling chamber 1210. The inhalation gas supply line 144 is
coupled with the breath-sampling chamber 1210, and is configured to
transport oxygen gas to the patient 101. The exhalation gas collection
line 143 is coupled with the breath-sampling chamber 1210, and is
configured to remove exhaled gases from the breath-sampling chamber 1210.

[0134] With further reference to FIG. 12, in accordance with an
embodiment, patient interface 110 also includes an interchangeable insert
120C that is disposed at a front of the breath-sampling chamber 1210. The
carbon-dioxide sampling device 1201 also includes a breath-sampling line
546, as previously described. Thus, patient interface 110 also includes a
breath-sampling line 546 configured to transport a sample of the exhaled
breath from the patient 101 collected by the carbon-dioxide collector
502. The interchangeable insert 120C includes a breath-sampling port 501
that is configured to couple the breath-sampling line 546 with the
carbon-dioxide collector 502. The breath-sampling line 546 is configured
to transport a sample of exhaled breath from the patient 101 collected by
the carbon-dioxide collector 502. A portion of the breath-sampling line
546 proximate to the breath-sampling chamber 1210 is securely attached to
the breath-sampling chamber 1210, and is configured to prevent accidental
interference by the patient 101 with the breath-sampling line 546. By way
of example, the breath-sampling chamber 1210 may be configured as a
respiration chamber of a breathing mask 110, without limitation thereto.

[0135] With further reference to FIG. 12, in accordance with an
embodiment, the carbon-dioxide sampling device 1201 may also include a
carbon-dioxide indicator 1220 that is configured to indicate when a
threshold level of carbon dioxide is exceeded in the exhaled breath from
the patient 101. Thus, patient interface 110 includes the carbon-dioxide
indicator 1220 that is configured to indicate when a threshold level of
carbon dioxide is exceeded in the exhaled breath from the patient 101.
The carbon-dioxide indicator 1220 includes a visible portion that is
configured to change an appearance of the visible portion when a
threshold level of carbon dioxide is exceeded in the exhaled breath from
the patient 101. The carbon-dioxide indicator 1220 may also include a
visible portion that is configured to change color when a threshold level
of carbon dioxide is exceeded in the exhaled breath from the patient 101.
The carbon-dioxide indicator 1220 may be mounted conspicuously on a
portion of the carbon-dioxide sampling device 1201 to be readily
observable by an attendant of the patient 101.

[0136] With reference now to FIG. 13, in accordance with an embodiment, a
cross-sectional view 1300 is shown of patient interface 110 taken along
line 13-13 of FIG. 12. FIG. 13 illustrates the carbon-dioxide sampling
device 1201 including the breath-sampling chamber 1210, and a
carbon-dioxide collector 502. As shown in FIG. 13, component parts of the
breath-sampling chamber 1210 are also shown in cross-section, for
example, frame 125, facial skin interface 130, compliant nose bridge seal
135, and interchangeable patient interface insert 120C, covering the
patient's mouth and/or nose. Thus, the breath-sampling chamber 1210 is
configured to be disposed over a patient's mouth and nose, as shown. In
other embodiments, a similar breath-sampling chamber may be disposed over
only the nose or only the mouth of a patient. The breath-sampling chamber
1210 is also configured to seal with a patient's face preventing
unintentional leakage of respiratory gases from the breath-sampling
chamber 1210. The carbon-dioxide collector 502 is disposed in the
breath-sampling chamber 1210, and is fluid dynamically isolated from flow
of fresh respiratory gases such that exhaled breath may be captured
therein and directed toward breath-sampling line 546. The carbon-dioxide
collector 502 is configured to be disposed in proximity to, and outside
of, a respiratory opening (nose, mouth, or nose and mouth) of the patient
101, and to collect a sample of exhaled breath from the patient 101. As
shown in FIG. 13, the carbon-dioxide collector 502 includes an upper
portion 502-1 of the breath scoop 502, a lower portion 502-2 of the
breath scoop 502, and a breath-scoop channel 502-3. The upper portion
502-1 of the breath scoop 502 and the lower portion 502-2 of the breath
scoop 502 are designed to capture the patient's breath either from the
nose or the mouth of the patient 101, is indicated by the respective
arrows in FIG. 13 directed from the patient's nose and mouth, with
substantially no dilution with respiratory gases supplied to the patient
101. The breath-sampling line 546 is also shown in FIG. 13; unlike other
elements of the figure, the breath-sampling line 546 is not shown in
cross-section, but rather, lies generally outside of the plane of the
figure, for the purpose of facilitating the description. The
carbon-dioxide collector 502 communicates with the breath-sampling line
546 through the breath-sampling port 501. Thus, the carbon-dioxide
collector 502 is configured to collect a sample of the exhaled breath
from the patient 101 that is substantially undiluted by respiratory gases
supplied for the patient's breathing.

[0137] With further reference to FIG. 13, in accordance with an
embodiment, the carbon-dioxide sampling device 1201 may further include a
carbon-dioxide sensor (not shown) that is configured to sense a level of
carbon dioxide in the exhaled breath of the patient 101, and to output a
carbon-dioxide sensor signal commensurate with the level of carbon
dioxide. In one embodiment, the carbon-dioxide sensor may be co-located
with the carbon-dioxide collector 502, so that a sensor signal
commensurate with the content of carbon dioxide in the breath of the
patient 101 may be obtained as close as possible to the source of exhaled
breath, yet non-invasively. Thus, the carbon-dioxide collector 502 may
include the carbon-dioxide sensor.

[0138] With reference now to FIGS. 14 and 15, in accordance with
alternative embodiments, a schematic diagram 1400 is shown of a
carbon-dioxide analyzer 1401 of one embodiment in FIG. 14; and, a
schematic diagram 1500 is shown of a carbon-dioxide analyzer 1401 of an
alternative embodiment in FIG. 15. The carbon-dioxide sampling device
1201 may also include the carbon-dioxide analyzer 1401 of either
embodiment. As shown in FIG. 14, the carbon-dioxide analyzer 1401 is
configured to determine, from a sample of exhaled breath from the patient
101, a measurement of carbon-dioxide content in the sample of exhaled
breath from the patient 101. As shown in the alternative embodiment of
FIG. 15, for example, for a carbon-dioxide sensor that may be co-located
with the carbon-dioxide collector 502, the carbon-dioxide analyzer 1401
is configured to convert a sensor signal received from the carbon-dioxide
sensor into a measurement of carbon dioxide content in the sample of
exhaled breath from the patient 101. The carbon dioxide analyzer 1401
also includes a carbon-dioxide analysis protocol executor 1402 to provide
an accurate measurement of carbon dioxide content in the sample of the
exhaled breath from the patient 101 that is substantially unaffected by
dilution from respiratory gases supplied for the patient's breathing.
Both the carbon-dioxide analyzer 1401 and the carbon-dioxide analysis
protocol executor 1402 may include: hardware, firmware, hardware and
software, firmware and software, hardware and firmware, and hardware and
firmware and software, any of which are configured to assist in the
analysis of the sample of exhaled breath from the patient 101 to obtain a
measurement of carbon dioxide content that is substantially undiluted by
respiratory gases supplied for the patient's breathing. Moreover, the
carbon-dioxide analyzer 1401 and the carbon-dioxide analysis protocol
executor 1402 may be configured as separate electronic devices that are
separate from any ventilator 160 used to ventilate a patient 101 with
respiratory gases. The carbon-dioxide analyzer 1401 and the
carbon-dioxide analysis protocol executor 1402 may include, by way of
example without limitation thereto, a computer system.

[0139] With reference now to FIG. 16, in accordance with an embodiment, a
flowchart 1600 is shown of a method for non-invasively measuring carbon
dioxide in exhaled breath of a patient. The method includes the following
operations. At 1610, a carbon-dioxide collector is disposed in proximity
to, and outside of, the nose and mouth of the patient. At 1620, a sample
of exhaled breath is collected from the patient. The sample of the
exhaled breath from the patient is substantially undiluted by respiratory
gases supplied for the patient's breathing, for example, as described
above, by means of the breath scoop 520. The method may further include
the following operations. At 1630, a level of carbon dioxide in the
exhaled breath of the patient is sensed with a carbon-dioxide sensor. At
1640, a sensor signal is output that is commensurate with the level of
carbon dioxide. At 1650, the sensor signal is converted into a
measurement of carbon dioxide content in the sample of exhaled breath
from the patient with the carbon-dioxide analyzer. In addition, at 1660,
a carbon-dioxide analysis protocol may be applied to provide an accurate
measurement of carbon dioxide content in the sample of the exhaled breath
from the patient that is substantially unaffected by dilution from
respiratory gases supplied for the patient's breathing.

Section 5

A Carbon-Dioxide Sampling System for Accurately Monitoring Carbon Dioxide
in Exhaled Breath

[0140] With reference now to FIG. 17, in accordance with an embodiment, a
schematic diagram 1700 is shown of a carbon-dioxide sampling system 1701
for accurately monitoring carbon dioxide in exhaled breath. Herein,
"accurately" refers to measuring carbon dioxide levels closely to their
actual (true) values. The carbon-dioxide sampling system 1701 includes a
ventilator 160. The ventilator 160 is configured to ventilate a patient
101 with respiratory gases. The ventilator 160 includes a carbon-dioxide
sampling control unit 160-1, and a carbon-dioxide analyzer 1401. Although
similar to the carbon-dioxide analyzer 1401 described above, in contrast
with the carbon-dioxide analyzer 1401 described above, the carbon-dioxide
analyzer 1401 is configured as an integral part of the ventilator 160,
and therefore, is also configured as an integral part of the
carbon-dioxide sampling system 1701. The carbon-dioxide sampling control
unit 160-1 is configured to control the timing of sampling of carbon
dioxide in the exhaled breath of a patient 101, and to control the timing
of an analysis of exhaled gases by the carbon-dioxide analyzer 1401. The
carbon-dioxide sampling control unit 160-1 may include: hardware,
firmware, hardware and software, firmware and software, hardware and
firmware, and hardware and firmware and software, any of which are
configured to assist in the sampling of the sample of exhaled breath from
the patient 101 to obtain a measurement of carbon dioxide content that is
substantially undiluted by respiratory gases supplied for the patient's
breathing. Thus, the carbon-dioxide sampling control unit 160-1 is
configured to control collection of a sample of exhaled breath from the
patient 101 that is substantially undiluted by respiratory gases supplied
for the patient's breathing.

[0141] With further reference to FIG. 17, in accordance with an
embodiment, the ventilator 160 further includes a ventilation timing unit
160-2. The ventilation timing unit 160-2 may include: hardware, firmware,
hardware and software, firmware and software, hardware and firmware, and
hardware and firmware and software, any of which are configured to assist
in ventilating a patient 101 at regular intervals based on measured
levels of carbon dioxide in the breath of the patient 101. The
carbon-dioxide analyzer 1401 is configured to regulate the ventilation
timing unit 160-2 to ventilate a patient 101 at regular intervals based
on measured levels of carbon dioxide in the breath of the patient 101.
The carbon dioxide analyzer 1401 may also include an analysis protocol
executor 1402 to provide an accurate measurement of carbon dioxide
content in the sample of the exhaled breath from the patient 101 that is
substantially unaffected by dilution from respiratory gases supplied for
the patient's breathing, as previously described.

[0142] With further reference to FIG. 17, in accordance with an
embodiment, the carbon-dioxide sampling system 1701 may also include a
breath-sampling chamber 1210. As previously described, the
breath-sampling chamber 1210 is configured to be disposed over a
respiratory opening of a patient (nose, mouth, or nose and mouth), and is
configured to seal with a patient's face preventing unintentional leakage
of respiratory gases from the chamber. Moreover, the breath-sampling
chamber 1210 is configured to be coupled to the ventilator 160, as an
integral part of the carbon-dioxide sampling system 1701. The
carbon-dioxide sampling system 1701 may further include a carbon-dioxide
collector 502, as previously described, which is disposed in the
breath-sampling chamber 1210. The carbon-dioxide sampling system 1701 may
further include an exhalation-gas collection line 143, as previously
described, coupled to the breath-sampling chamber 1210 configured to
collect exhaled gases in a breath exhaled by the patient 101, and to
transport the exhaled gases to the carbon-dioxide analyzer 1401.

[0143] With reference now to FIG. 18, in accordance with an embodiment, a
front perspective view 1800 is shown of patient interface 110 of a
combined non-invasive ventilation patient interface 110 and
carbon-dioxide sampling system 1701. The combined interface 110 and
system 1701 includes patient interface 110, and a carbon-dioxide sampling
system 1701, as described above in the discussions of FIGS. 9 and 14,
respectively. The breath-sampling chamber 1210 includes a respiration
chamber of a breathing mask 110. The combined patient interface 110 and
carbon-dioxide sampling system 1701 may further include a separate
breath-sampling line 546 that is configured to transport a sample of the
exhaled breath from the patient 101 to the carbon-dioxide analyzer 1401.
The combined patient interface 110 and carbon-dioxide sampling system
1701 may also include an inhalation gas supply line 144 and an exhalation
gas collection line 143. The inhalation gas supply line 144 is coupled
with the breath-sampling chamber 1210, and is configured to transport
oxygen gas to the patient 101. The exhalation gas collection line 143 is
coupled with the breath-sampling chamber 1210, and is configured to
remove exhaled gases from the breath-sampling chamber 1210. In an
alternative embodiment, the exhalation gas collection line 143 may be
configured to transport a sample of the exhaled breath from the patient
101 to the carbon-dioxide analyzer 1401, instead of the separate
breath-sampling line 546. The exhalation-gas collection line 143 is
securely attached to the breath-sampling chamber 1210, and is configured
to prevent accidental interference by the patient 101 with the
exhalation-gas collection line 143. The combined patient interface 110
and carbon-dioxide sampling system 1701 may also include a carbon-dioxide
indicator 1220, as previously described in the discussion of FIG. 12. The
carbon-dioxide indicator 1220 is configured to indicate when a threshold
level of carbon dioxide is exceeded in the exhaled breath from the
patient 101. The carbon-dioxide indicator 1220 is mounted conspicuously
on a portion of the mask 110 to be readily observable by an attendant of
the patient 101.

[0144] With reference now to FIG. 19, in accordance with an embodiment, a
schematic diagram 1900 is shown of the carbon-dioxide analyzer 1401. The
carbon-dioxide analyzer 1401 may further include a carbon-dioxide sensor
1901. The carbon-dioxide sensor 1901 is configured to sense a level of
carbon dioxide in the exhaled breath of the patient 101, and to output a
sensor signal commensurate with the level of carbon dioxide. The carbon
dioxide analyzer 1401 may also include a sensor-signal converter 1902.
The sensor-signal converter 1902 may include: hardware, firmware,
hardware and software, firmware and software, hardware and firmware, and
hardware and firmware and software, any of which are configured to
convert the sensor signal into a measurement of carbon dioxide content in
the sample of the exhaled breath from the patient 101. Thus, the
sensor-signal converter 1902 is configured to convert the sensor signal
into a measurement of carbon dioxide content in the sample of the exhaled
breath from the patient 101. The carbon-dioxide analyzer 1401 may further
include an analysis protocol executor 1402. The analysis protocol
executor 1402 is configured to provide an accurate measurement of carbon
dioxide content in the sample of the exhaled breath from the patient 101
that is substantially unaffected by dilution from respiratory gases
supplied for the patient's breathing, as previously described. The
carbon-dioxide sensor 1901 may include an infra-red detector 1901-1, and
a source of infra-red radiation 1901-2. The infra-red detector 1901-1, by
way of example, without limitation thereto, may be a semiconductor
photo-diode. The infra-red detector 1901-1 is configured to measure the
absorbance of infra-red radiation at a frequency within an absorption
band of carbon dioxide for the infra-red radiation, and to generate a
sensor signal commensurate with the level of carbon dioxide based on
absorbance.

[0145] With reference now to FIG. 20, in accordance with an embodiment, a
schematic diagram 2000 is shown of a combination 2001 of a carbon-dioxide
measurement display 2001-2 and a carbon-dioxide measurement recorder
2001-1. The carbon-dioxide measurement recorder 2001-1 may be a computer
system and/or the memory of a computer system, without limitation
thereto. As shown in FIG. 20, the carbon-dioxide measurement display
2001-2 may be configured to display data from the ventilator 160, for
example, such as: respiration rate, indicated by the sinusoidal waveform
on the carbon-dioxide measurement display 2001-2; the activity of the
ventilator 160 in supplying respiratory gases, for example, oxygen, to
the patient 101, indicated by the square-wave waveform; and, a textual
display of the partial pressure of carbon dioxide in exhaled breath,
PECO2. As shown in FIG. 20, the partial pressure of carbon
dioxide in exhaled breath may be displayed as a decimal number in units
of pressure, given in units of millimeters of mercury (mm Hg), without
limitation thereto.

[0146] With reference now to FIG. 21, in accordance with an embodiment, a
flowchart 2100 is shown of a method for accurately monitoring carbon
dioxide in exhaled breath of a patient. The method includes the following
operations. At 2110, a sampling of carbon dioxide in an exhaled breath of
a patient is timed with a carbon-dioxide sampling control unit.

[0147] At 2120, the timing of an analysis of gases in an exhaled breath of
a patient is controlled with a carbon-dioxide analyzer. The
carbon-dioxide sampling control unit is configured to control collection
of a sample of the exhaled breath from the patient that is substantially
undiluted by respiratory gases supplied for the patient's breathing.
Therefore, the collection of the exhaled breath sample may be timed not
to coincide with a time when respiratory gases, for example, oxygen, are
being supplied to the patient. The method may also include the following
operation. At 2130, a ventilation timing unit is regulated to ventilate a
patient at regular intervals based on measured levels of carbon dioxide
in the breath of the patient. In addition, at 2140, a carbon-dioxide
analysis protocol may be applied to provide an accurate measurement of
carbon dioxide content in the sample of the exhaled breath from the
patient that is substantially unaffected by dilution from respiratory
gases supplied for the patient's breathing.

Section 6

Interchangeable Inserts

[0148] Various embodiments provide a ventilation mask with a removable
insert. In one embodiment, the front portion of the mask is removable to
enable access to a respiratory opening region such as either the mouth,
nose region, or both the mouth and nose regions of a patient without
requiring removal of the entire mask and strap system. The nose region
would comprise at least the nasal (nose) opening and may further comprise
one to several centimeters surrounding the nasal opening. The mouth
region would comprise at least the oral (mouth) opening and may further
comprise one to several centimeters surrounding the oral opening. This
enables quick access to the mouth and/or nose region while simultaneously
ventilating the patient.

[0149] The removable insert enables a caregiver access to the mouth
and/nose region of the patient that would be inaccessible with a
conventional ventilation mask on the patient. With a conventional mask,
the entire mask and strapping system would need to be removed to gain
access to the nose and/or mouth region of the patient. Thus, the
removable insert of saves considerable time because mask adjustment is
significantly reduced, especially when access to the mouth and/or nose
region of the patient is desired.

[0150] The removable insert enables the patient to perform many tasks
while being simultaneously ventilated. For example, a patient can eat,
take medication, brush teeth, talk, etc., with the insert removed. It
should be appreciated that the patient is still ventilated even with the
removable section of the mask removed from the frame portion.

[0151] Referring back to FIG. 1, domed front portion 120 is removable from
frame portion 125 to enable access to the mouth and/or nose region of the
patient without requiring removal of the frame portion 125 from the
patient. In this embodiment, the mouth and/or nose region of the patient
can be accessed without removing or adjusting strapping system 111.

[0152] Referring back to FIG. 3, a front perspective view of patient
interface 110 of a non-invasive ventilation system 160 is shown and
illustrates removal/insertion of an interchangeable patient interface
insert 120A, in accordance with an embodiment. As depicted,
interchangeable patient interface insert 120A is in the removed position
to enable access to the nose and/or mouth region of the patient.
Interchangeable patient interface insert 120A includes exhaust gas vent
ports 123, and is thus designed for use in a vented non-invasive
ventilation application. Interchangeable patient interface insert 120A
includes one or more tabs 302 (one visible) which correspond with, and
seat into, slots 303 that are disposed in the semi-elliptical rim 304 of
frame 125. Be applying a pinching pressure on grip regions 121-1 and
121-2 (as illustrated by arrows 301), interchangeable patient interface
insert 120A can be compressed slightly so that tabs 302 can be seated
into slots 303 and interchangeable patient interface insert 120A can be
removably coupled with frame 125. Reversal of the installation process
allows for the removal of interchangeable patient interface insert 120A.

[0153] It is appreciated that when the removable insert 120A is in the
removed position, the patient is still receiving gas flow from limb 143
because the airflow enters the frame portion 125 of the mask. The
removable insert enables simultaneous ventilation and access to the mouth
and/or nose region of the patient.

[0154] In one embodiment, the removable insert includes a graphic or color
on the outside surface (facing away from the patient) so the patient can
have a customized look. For example, a portion of the removable insert
may be opaque or a color such as orange, red, or blue (or configured with
multiple colors). Some non-limiting examples of a graphic include: a
handlebar mustache, stars, a rainbow, a beard, chin whiskers, a monster
face, a smiley face, etc. In another embodiment, the inside surface of
the removable insert is scented, such as with cinnamon scent, mint scent,
citrus scent, bubble gum scent, or other scent, to provide a pleasing
scent to the patient while being ventilated. It is appreciated that the
removable insert 120A may be dosed with medication for a controlled
release to the patient via either a nasal entry or mouth entry.

[0155] In another embodiment, therapeutic devices can be incorporated with
the removable insert. For example, a bite plate on the inside surface can
be incorporated into the removable insert to function as both a bite
plate and a cover for the mask. It is appreciated that any number of
therapeutic devices could be incorporated with insert 120A on the inside
surface (facing patient) and/or on the outside surface (facing away from
the patient).

[0156] The removable insert may also be coated in the inside surface with
an anti-fogging layer to reduce fogging on the inside surface. Anti-fog
coating assists in maintaining a transparent surface which allows an
unimpeded view of the nose and lips of a patient, so that a caregiver may
easily assess the patient without requiring removal of either patient
interface 111 or removable insert 120A (or other removable insert 120
which is coated with anti-fog coating on its interior surface).

[0157] Referring now to FIG. 22, a method 2200 for accessing a mouth
and/or nose region of a ventilated patient is provided. In one
embodiment, access to the mouth and/or nose region of a patient is
provided while simultaneously ventilating the patient. With method 2200
of, mouth and/or nose region access can be achieved without requiring
removal of the mask or mask strapping system from the patient. At 2202,
2200 includes ventilating the patient.

[0158] At 2204, method 2200 includes accessing a frame portion of a mask
surrounding the mouth and/or nose region of the patient wherein the frame
region is coupled with a semi-rigid retention strap for maintaining
positive pressure between the frame portion and the mouth region of the
patient.

[0159] At 2206, 2200 includes removing a removable insert that is
configured to physically attach and detach from the frame portion without
requiring removal of said frame portion or said retention strap from said
patient while simultaneously ventilating the patient.

[0160] After the removable insert is removed, access to the nose and/or
mouth region of the patient is achieved while simultaneously ventilating
the patient.

[0161] It is appreciated that the replaceable insert can be used for any
number of functions. For example, the removable insert can be selected to
provide a therapeutic function to the patient such as a bite block, drug
delivery, oral and/or nasal care, feeding, suction, etc. The removable
inserts can be configured with any number of ports, filters, drug
delivery systems, etc., and can also be colored or include a graphic
design. The removable insert enables access to the nose and/or mouth
region of the patient while not interrupting ventilation of the patient
or requiring removal of the mask from the patient.

Section 7

Lateral Gas Line Configuration

[0162] Various embodiments described herein include a lateral
configuration of gas delivery limbs coupled with a ventilation mask. The
lateral configuration can be used in single limb applications as well as
multiple limb applications. However, a dual configuration using bilateral
limbs facilitates a cross flow of air across a respiratory opening region
(i.e., at least the nose opening and/or mouth opening) of a patient which
purges dead space and thus improves ventilation of the patient. In one
embodiment, the lateral gas line configuration enables ventilation of a
patient even with a removable front portion of the mask in the removed
position. This lateral configuration of the gas delivery limbs
facilitates access to the nose and/or mouth region of the patient while
simultaneously ventilating the patient. While only bilateral limbs are
depicted (limb on each lateral side of a patient interface and thus on
each side of a patient's face when donned), it is appreciated that only
one lateral limb, on either lateral side of the patient interface, may be
utilized in some embodiments.

[0163] The lateral gas line configurations described herein are also
configured to improve comfort and stability of the mask on the patient.
For example, in one embodiment, a gas limb is coupled with the mask via a
swivel connection which enables the gas limb to swivel with respect to
the mask. The swivel mount(s) between the gas limb and the mask frame
enables free movement of the gas limb(s) without imparting torque on the
mask itself. By reducing the torque on the mask frame, even pressure can
be achieved between the mask and the patient, thus improving patient care
and comfort.

[0164] Referring back to FIG. 1, a bilateral gas line configuration is
shown. Breathing circuit 140 includes limbs 143 and 144 which are shown
to be disposed in a lateral configuration with respect to the temporal
region of the patient. The limb (143, 144) may be coupled to the frame
portion 125 via a swivel port connection which enables the limb to rotate
with respect to the frame portion 125 without imparting torque to the
frame portion of the mask. It is appreciated that the swivel connection
between the frame portion 125 and the limb enables the limbs to be moved
from a lateral position to a front position shown in FIG. 2 where the
limb 143 is shown to be rotated to the front of the patient. In this
embodiment, the limbs 143, 144 are positioned such that the patient can
lay on the side of their head without having a breathing tube in the way
or interfering with ventilation. In one embodiment, limbs 143 and 144 are
coupled at Y connector 142 where the Y connector 142 includes one or more
swivel connectors.

[0165]FIG. 3 shows a bilateral gas line configuration with breathing
limbs 143 and 144 positioned laterally with respect to the patient's
head. In this embodiment, a front removable insert 120A is shown in the
removed position. With the lateral gas line configuration described
herein, ventilation can occur with the front removable insert in the
removed position because the gas flow is configured to flow across a
respiratory opening region (i.e., at least the nose opening and/or mouth
opening) of the patient. With the removable insert in the removed
position, gas flow can still be delivered to the patient. The described
lateral gas line configurations facilitate simultaneous ventilation of a
patient while enabling access to the mouth and/or nose region of the
patient.

[0166] Referring back to FIG. 7, one or more limb of breathing circuit 140
may be coupled with strap system 111. For example, region 715 may include
a fastener to removably couple limb 143 to side strap 112 of strap system
111. In this embodiment, at least one portion of the breathing circuit
140 is configured in a parallel relationship with a strap 112 of strap
system 111. It is appreciated that orifices 722 may be configured as
swivel connections that enable swivel movement of the connected device or
tube.

[0167] In one embodiment, gas delivery orifices 722 are non-concentric
with respiratory opening regions (mouth opening region and nasal opening
regions) of a patient. In other words, gas delivery orifice(s) 722 are
shifted laterally, away from the midline, with respect to any of these
openings. Furthermore, gas delivery orifice 722-1 and 722-2 are shifted
laterally with respect to front portion 120; that is, they do not define
an opening through any part of front portion 120.

Section 8

Quick Donning Headgear

[0168] Various embodiments include a quick donning headgear for patient
ventilation. The quick donning headgear described herein enables quick
and intuitive application and removal of the headgear so as to improve
patient care and reduce time spent donning and removing the headgear from
the patient.

[0169] In some embodiments, the headgear apparatus includes a semi-rigid
strap system that enables intuitive application to the patient. The
semi-rigid straps maintain a head-shape of the strap system even when not
in use. The semi-rigid design enables faster donning of the headgear as
opposed to conventional strap systems because the straps are already
pre-arranged in the proper configuration prior to use, thus reducing the
effort and/or time involved in applying and/or removing the device. The
semi-rigid shape also requires less adjustment compared to conventional
strapping systems because it is already in the shape of a human head. It
is appreciated that any portion(s) of head strap 111 may include a ridged
or semi-rigid material. It is also appreciated that the semi-rigid
material may be flexible.

[0170] Referring back to FIG. 1, head strap 111 includes side straps 112
(112-1, 112-2, 112-3 and 112-4 (not visible in FIG. 1, but illustrated in
FIG. 7). In one embodiment, any portion of straps 112 could be formed of
a ridged or semi-rigid material and/or may have elastic properties. In
one embodiment, straps 112 retain a head like shape when not applied to a
patient.

[0171] In one embodiment, straps 112 may include a portion that is
semi-rigid and also flexible so that the head shape can be expanded for
larger patients without requiring adjustment of straps 112 at the frame
portion 125. The head-shape of the strap system 111 also enables greater
securing force distribution between the patient's skin and the mask
structure because less adjustment is required. Depending on the
configuration (nasal, oral, or oral/nasal) of a patient interface 110
which is utilized with strap system 111, the head-shape of the strap
system 111 evenly distributes the force around either the patient's mouth
region, nose region, or both the mouth region and nose region to reduce
possible skin irritations and improve patient comfort.

[0172] Referring back to FIG. 7, in some embodiments, one or more of side
straps 112 may be configured to change color, such as from opaque to
translucent or from opaque to transparent, or from a lighter shade to a
darker shade, in response to stress being applied to the side strap 112
which is indicative of over tightening of the side strap 112. Similarly,
in some embodiments, one or more of side straps 112 may be configured to
change color, such as from opaque to translucent or from opaque to
transparent, or from a lighter shade to a darker shade such that an
embedded colored thread 712 becomes visibly exposed via the non-patient
facing side of a side strap 112 in response to stress being applied to
the side strap 112 which is indicative of over tightening of the side
strap 112.

[0173] Referring back to FIG. 2, the quick donning headgear system 111 may
include a quick release tab 212 that can be used for rapid removal of the
patient interface 110 from the patient in the event of an emergency. The
quick release tab 112 can also be used in donning of the headgear to as
to adjust the position of the strap system 111 on the patient's head.

[0174] The semi-rigid construction of head strap system 111 provides some
amount of inherent rigidity so that when it is in storage, it can be
collapsed; but when it's removed from collapsed storage, it easily and
naturally returns to a general head shaped structure, so that it is
visibly obvious how to position and install head strap system 111 on
patient 101 when donning patient interface 110. In this manner, there is
no need to sort out where the front, back, top, or bottom is located. In
one embodiment, patient interface 110 is packaged with head strap system
111 already pre-attached with frame 125, so that when unpackaged the
semi-rigid structure of head strap system 111 causes it to look somewhat
like a helmet that can just be pulled quickly over the head and face area
of patient 101, much like putting on a catcher's mask.

Section 9

Smart Connections

[0175] Various embodiments include "smart connectors" for use with patient
ventilators. "Smart" refers to a feature that is user friendly and aids
in or prevents misconnections with a ventilator that would configure
ventilation improperly for a patient. The smart connectors enable proper
configuration of a ventilation system and also can be used to determine
continuity of the system. For purposes of the present description, the
term "continuity" is used to describe the physical continuity of the
ventilation system, meaning that correct parts are used and that the
correct parts are properly connected and functioning properly.

[0176] In one embodiment, physical similarities and dissimilarities of
various ventilation components are used to enable compatible parts to
couple together while preventing dissimilar or non-compatible parts from
being used. In this way, non-compatible parts are not physically able to
couple with non-compatible parts, thus preventing an improper
configuration of the system from being used with a patient. Moreover,
with respect to the proper connection point, there may be only one
orientation in which a smart connector can be coupled to the connection
point on the ventilator (in order to prevent inadvertent misconnection).
This may be accomplished via design feature (shape), labeling, color
coding, or combination of these features. In another embodiment,
identifiers such as color, barcode, RFID, etc. are used to distinguish
similar and dissimilar parts.

[0177] For example, in one embodiment, different classes of parts (e.g.,
for various patient populations, flow rated, type of ventilation, etc.)
can be configured to have unique connector ends that only enable
compatible parts to mate with. The special physical configuration of
various parts also prevents non-compatible parts to be used.

[0178] In another embodiment, the ventilation parts can be color coded. In
this embodiment, parts with the same color can be considered compatible
and can be used together. Parts with different colors can be considered
non-compatible and should not be used together. When looking at a
ventilation configuration, a part with a different color from the rest is
easily identified as non-compatible and should be replaced with a
compatible part with the same color as the rest. In one embodiment,
different ventilation methods (e.g., single or dual limb) have different
colors indicating different uses. In another embodiment, different
colored parts are used to differentiate parts for different patient
populations.

[0179] In another embodiment, parts with different colors can be
compatible. In this embodiment, semi-transparent parts of various colors
can be used to create "good" colors and "bad colors." For example, a
yellow part can be combined with a blue colored part to create a "good"
color of green while a blue part combined with a red part create a "bad"
color of purple. It is appreciated that any number of colors, patterns,
pictures or any other unique markings could be used in accordance with
the embodiments described herein to distinguish ventilation parts.

[0180] In another embodiment, various parts of the ventilation system can
include a machine readable code or identifier that enables tracking and
monitoring of the parts of the ventilation system. For example, in one
embodiment, one or more parts of the ventilation system include a barcode
or RFID tag that enables identification of the parts and enabled
determination of system configuration. In this embodiment, part
compatibility can be verified and system configuration can be verified.
In one embodiment, the ventilator includes a reader that can read the
identifier associated with the parts to determine compatibility and/or
system configuration.

[0181] In another embodiment, one or more parts of the ventilation system
include an electrical lead for enabling a continuity check of one or more
portions of the ventilation system. When various parts with the wire lead
are coupled, a continuous wire lead is established between the parts. A
signal can be passed through the lead to check the lead is continuous. In
this embodiment, inadvertent disconnection between any of the parts can
be detected, thus improving patient care and ventilation functions.

[0182] Referring to FIG. 23, a ventilator 160 is shown comprising a signal
reader 2300 and a configuration determiner 2305. The breathing circuit
140 includes a wire lead 2304 for enabling the signal reader 2300 to
determine continuity of at least a portion of breathing circuit 140. In
one embodiment, the signal reader 2300 provides a signal to the
electrical lead 2304 and determines continuity based on the signal
returned.

[0183] In one embodiment, the signal can also be used to determine a
configuration of the ventilation system. For example, various parts can
have electrical components that enable the signal reader to identify
which parts are in the system and can determine their configuration based
on sending and receiving a signal over electrical leas 2304.

[0184] In another embodiment, one or more parts of the ventilation system
include a machine readable identifier such as an RFID or barcode. In this
embodiment, the signal reader 2300 is configured to read the
corresponding barcode and/or RFID to perform system configuration and
continuity checks. It is appreciated that in one embodiment, the
configuration determiner 2305 is also configured to determine
configuration information based on the RFID signal and/or barcode
information.

[0185] Referring to FIG. 24, a method 2400 for checking continuity of a
breathing circuit is provided. At 2402, a signal is provided to a first
end of an electrical lead of a breathing circuit. In one embodiment, one
or more parts of the ventilation system include a wire lead that can be
used to transmit a signal to determine continuity of that part and/or any
parts coupled with that part.

[0186] At 2404, the signal is transmitted to a second end of the
electrical lead. Provided the electrical lead is continuous, at 2406, the
signal is received at a second end of the electrical lead and at 2408, it
can be determined that the breathing circuit is continuous based on the
received signal.

[0187] Provided the electrical lead is non-continuous, at 2410, the signal
is not received at a second end of the electrical lead and at 2412, it
can be determined that the breathing circuit is non-continuous based on
the received signal. At this point, an alert can be generated to signal
the breathing circuit is discontinuous and may need to be reconfigured.

[0188] Referring now to FIG. 25, a method 2500 for determining
configuration of a breathing circuit is provided. At 2502, a signal is
provided at a first end of an electrical lead of a breathing circuit. At
2504, the signal is transmitted to a second end of the electrical lead.
At 2506, the signal is received at the second end of the electrical lead.
At 2508, configuration of the breathing circuit is determined based on
the signal received.

[0189] In one embodiment, as the signal is transmitted through the
electrical lead, any number of modifications to the signal could be
performed by any number of components in the system. The modification of
the signal enables the signal reader 2300 of FIG. 23 to determine
configuration of the breathing circuit. For example, a "smart" connector
may include a microchip that enables access to real-time data associated
with the part or the ventilation system as a whole.

Section 10

Tube Placement in Non-Invasive Ventilation

[0190] FIGS. 26A-26C illustrate detail views of a self-sealing tube
insertion region 630, according to various embodiments. Some embodiments
of a self-sealing tube insertion region 630 were previously described in
conjunction with FIG. 6, and FIGS. 26A-26C further extrapolate on those
embodiments.

[0191] As illustrated, in FIG. 26A, bridge 631 and cushioning material 633
(which defines and includes self-sealing tube opening 632 may be
removably coupled with facial skin interface 130, in one embodiment. For
example, bridge 631 may be coupled to facial skin interface 130 via an
adhesive with a low shear force which may be used one or more times
without exhausting its adhesion abilities. Additionally or alternatively,
bridge 631 may be positioned and then held in place (as depicted in FIG.
6) by the securing force which is supplied by head strap system 111. By
being removably coupled with facial skin interface 130, a portion of the
tube insertion region can be decoupled from patient interface 110 when
patient interface 110 is doffed. Tube 647 may be an orogastric tube,
nasogastric tube, or carbon dioxide sampling tube. If tube 647 is
orogastrically or nasogastrically inserted into patient 101, then this
portion of tube insertion region can be decoupled from patient interface
110 when patient interface 110 is doffed. This allows the tube 647 to
remain in place, without being removed or having its function interfered
with in anyway by the doffing of patient interface 110.

[0192] As depicted in FIG. 26A self-sealing tube insertion region 630 can
be coupled or decoupled with facial skin interface 130 and self-seals
about tube 647 when tube 647 is disposed in opening 632, between the
facial skin of patient 101 facial skin interface 130. As previously
described, bridge 634 diverts this securing force around tube 647 while
tube 647 is inserted in opening 632. Cushioning material 633 may be foam,
silicone, TPE, or other cushioning material. In one embodiment, bridge
631 and cushioning material 633 may be the same material but in different
thicknesses or configurations to provide different structural
functionality (e.g., bridging versus cushioning/sealing). Cushioning
material 633 seals opening 632 when tube 647 is not present expanding to
fill opening 632 which may be a piercing through cushioning material 633.
Similarly, cushioning material 633 conforms to tube 647, when inserted
into opening 632, and self-seals around tube 647 to prevent unintentional
leakage of gases from patient interface 110.

[0193] As depicted in FIG. 26B, in one embodiment, opening 632 may be a
slit 632A defined within cushioning material 633. Tube 647 may be an
orogastric tube, a nasogastric tube, a carbon dioxide sampling tube, a
respiratory gas sampling tube, or other type of tube. Tube 647 can be
inserted and removed from slit 632A without affecting positioning or
function of tube 647. For example, if tube 647 is orogastrically or
nasogastrically inserted into patient 101, tube 647 may be inserted or
removed into slit 632A without removing tube 647 or disturbing the
function of tube 647. Slit 632A comprises a self-sealing tube receiving
opening, in that cushioning material 633 expands to removably seal about
tube 647 when tube 647 is disposed in slit 632A. Similarly, cushioning
material expands to seal slit 632A closed when tube 647 is not present.
In some embodiments a removable, reusable (e.g., low shear force, low
tack) adhesive is applied within slit 632A to facilitate sealing of slit
632A when no tube is present in slit 632A and to facilitate removable
sealing of slit 632A about a tube 647 (when inserted).

[0194] As depicted in FIG. 26c, in one embodiment, opening 632 may be a
gap 632B defined in a bladder feature 836 of facial skin interface 130.
Gap 632B functions in a similar fashion to slit 632A. Gap 632B may be
defined in a single bladder 836 or in a space between a pair of adjacent
bladders 836. For example, if tube 647 is orogastrically or
nasogastrically inserted into patient 101, tube 647 may be inserted or
removed into gap 632B without removing tube 647 or disturbing the
function of tube 647. Gap 632B comprises a self-sealing tube receiving
opening, in that bladder feature 836 removably seals about tube 647 when
tube 647 is disposed in gap 632B. This sealing can be due to one or more
factors such as compressing of bladder feature 836 by the securing force
supplied by head strap system 111 and/or by inflation of bladder(s) 836
by inhalation gases present within patient interface 110 and supplied
from ventilator 160 (or by other source of gas or fluid). For example,
the bladder(s) 836 may be sealably inflated around tube 647. Similarly,
bladder feature 836 seals gap 632B closed when tube 647 is not present.
In some embodiments a removable, reusable (e.g., low shear force, low
tack) adhesive is applied within gap 632B to facilitate sealing of gap
632B when no tube is present in gap 632B and to facilitate removable
sealing of gap 632B about a tube 647 (when inserted). As can be seen,
tube 647 can be received in and removed from gap 632B independently of
the donning and doffing of patient interface 110. When tube 647 is
inserted within gap 632B, bladder feature 836 diverts the securing force
(supplied by head strap system 111) around tube 647 such that tube 647 is
not pressed against the facial skin of patient 101 to form a pressure
point.

Section 11

Non-Invasive Ventilation Exhaust Gas Venting

[0195] As described previously with reference to FIG. 7, in one
embodiment, filter media 123A can be used in conjunction with or in place
or exhaust gas vent ports 123 which have been depicted elsewhere herein.
Typically, exhaust gas vent ports 123 are open to the atmosphere. Instead
of open vent holes, in one embodiment, filter media 123A is included in
addition to vent ports 123 or alternatively utilized to replace vent
ports 123. Filter media 123A filters contagions (e.g., bacteria, viruses,
drugs (in particular aerosolized or nebulized drags), and/or chemicals)
from the exhaust gas which is exhausted through filter media 123A. The
exhausted gas may comprise exhaled breath, excess fresh respiratory gas,
or a combination thereof. In addition to filtering, filter media 123A
diffuses the gases that are exhausted there through. Filter media can be
composed of any known type of respiratory gas filter media, including,
but not limited to, paper, activated carbon, synthetic woven fiber (e.g.,
polyester, Gortex® or similar expanded polytetrafluoroethylene
(ePTFE)), open cell foam, glass fiber, natural woven fiber (e.g., bamboo,
cotton), or combination thereof.

[0196] In some embodiments, filter media 123A provides a controlled
pressure drop in addition to filtering contagions from exhaled gases as
the exhaled gases pass through. This controls an expulsion flow of
exhaled breath and can also control an intentional leak rate of fresh
respiratory gases from within patient interface 110. Such intentional
leak rate control can manage the pressure of fresh respiratory gases
within patient interface 110 such that a desired pressure range of
continuous positive airway pressure is achieved. A variety of factors
including one or more of composition, thickness, layers, surface area,
and porosity of the media of filter media 123A can be selected, in some
embodiments, to either filter contagions, provide a designated
flow/intentional leak rate to control internal pressure of patient
interface 110, or both.

[0197] In some embodiments, the filter media 123A can simultaneously
filter and vent, thus eliminating the need have separate vent holes. In
one embodiment, interchangeable patient interface insert 120D can be
removed and replaced with a new interchangeable patient interface insert
120D when filter media 123A becomes clogged, soiled, or has surpassed its
recommended replacement interval. In another embodiment, filter media
123A is, itself, replaceable.

[0198] In some embodiments, filter media 123A may be imbued with one or
more substances. For example in one embodiment, filter media 123A may be
imbued with a fragrance such as cinnamon, mint, peppermint, spearmint,
wintergreen, citrus, fruit, bubblegum or the like in order to mask odors
of exhaust gases which are not eliminated by filter media 123A. In one
embodiment, filter media 123A, may be imbued with a desiccant (e.g.,
silica, activated charcoal, or the like) in order to assist in
controlling moisture level on the interior of patient interface 110 to
reduce fogging and/or to improve patient comfort, and in order to
maintain filter media 123A in a dry state which is can kill viruses and
is non-conducive to formation of funguses. Along these lines, transparent
portions of domed front portion 120 or similar interchangeable insert
120D (and the like) may have interior portions coated with an anti-fog
coating to prevent fogging and to maintain transparency both for patient
comfort and so that medical personnel may easily view inside of patient
interface 110. In one embodiment, filter media 123A is imbued with an
antibacterial, antimicrobial, and/or antifungal substance (e.g., silver,
an antibiotic, etc.)

[0199]FIG. 27 illustrates a replaceable filter cartridge 2724, in
accordance with some embodiment. Filter cartridge 2724 is shown in an
uninstalled state. Arrow 2750 illustrates where filter cartridge 2724 may
be snap fit or otherwise coupled with interchangeable insert 120D, or a
similar interchangeable or non-interchangeable domed front portion 120.
This is one mechanism for changing for replacing filter media 123 when
clogged or past a time of suggested usability. In other embodiments,
filter media 123A is an integral portion of interchangeable insert 120D
(rather than a replaceable cartridge), and the entirety of
interchangeable insert 120D is removed and replaced in order to replace
filter media 123. In some embodiments a larger portion of interchangeable
insert 120D may be composed of filter media 123 than depicted in FIG. 27
or other figures herein. For example, in some embodiments up to the
entire visible exterior surface of interchangeable insert 120D may be
composed of one or some combination of filter materials.

Section 12

Non-Invasive Ventilation Facial Skin Protection

[0200] Many features for skin protection have been discussed previously
herein. Additional features which may be used alone or in combination
with the previously discussed skin protection features (or with other
skin protection features that are described in Section 13) include
features which eliminate fluid via wicking and/or purging, and features
which utilize an imbued substance to actively soothe/protect the facial
skin in one or more areas which receive contact from a patient interface
as a result of non-invasive ventilation.

[0201]FIG. 28 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal 135 and a facial skin interface
130, according to an embodiment. As illustrated by enlarged detail 2801,
the skin contacting portion of facial skin interface 130 is configured
with a plurality of micro-grooves 2825 which provide small passageways
between skin contacting peaks 2824 which allow air flow. In one
embodiment, micro-grooves 2825 may be 0.075 inches or narrower in width,
in another embodiment some of micro-grooves 2825 may be 0.050 inches or
narrower in width. In one embodiment, some or all of microgrooves 2825
may be between 0.075 and 0.005 inches in width. When patient interface
110 is donned and coupled with ventilator 160, pressurized fresh
respiratory gas flows through micro-grooves 2825 in a controlled and
intentional leak as illustrated by gas flow path 2826. This controlled
and intentional leak facilitates a controlled purging of moisture by both
forcing moisture out through micro-grooves 2825, and by evaporating
moisture. This controlled leak assists in purging moisture and thus
preventing accumulation of fluids (e.g., sweat, condensation, or the
like) and/or eliminating fluids from within facial interface 110 (the
portion which covers nose and/or mouth openings when donned) and from
between facial skin interface 130 and the facial skin of patient 101 that
is in contact with facial skin interface 130 when patient interface 110
is donned. In one embodiment, micro-grooves 2825 may be a
removable/replaceable component which is removably coupled with facial
skin interface 130. Thus when micro-grooves 2825 get clogged or exceed a
recommended service time, this replaceable component can be replaced.

[0202] As illustrated in FIG. 28 by enlarged detail 2833, the skin
contacting portion of compliant nose bridge seal 135 may additionally or
alternatively be configured with a plurality of micro-grooves 2835 which
provide small passageways between skin contacting peaks 2834 which allow
air flow. In one embodiment, micro-grooves 2835 may be 0.075 inches or
narrower in width, in another embodiment some of micro-grooves 2835 may
be 0.050 inches or narrower in width. In one embodiment, some or all of
microgrooves 2835 may be between 0.075 and 0.005 inches in width. When
patient interface 110 is donned and coupled with ventilator 160,
pressurized fresh respiratory gas flows through micro-grooves 2835 in a
controlled and intentional leak as illustrated by gas flow path 2836.
This controlled and intentional leak facilitates a controlled purging of
moisture by both forcing moisture out through micro-grooves 2835, and by
evaporating moisture. This controlled and intentional leak assists in
purging moisture and thus preventing accumulation of fluids (e.g., sweat,
condensation, or the like) and/or eliminating fluids from within facial
interface 110 (the portion which covers nose and/or mouth openings when
donned) and from between compliant nose bridge seal 135 and the facial
skin of patient 101 that is in contact with compliant nose bridge seal
135 when patient interface 110 is donned. In one embodiment,
micro-grooves 2835 may be a removable/replaceable component which is
removably coupled with compliant nose bridge seal 135. Thus when
micro-grooves 2835 get clogged or exceed a recommended service time, this
replaceable component can be replaced.

[0203] As illustrated in FIG. 28, in one embodiment, facial skin interface
130 additionally or alternatively includes an extended. Chin portion 832,
which may include a chin bellows 2850 and/or a jaw bellows 2855. Chin
bellows 2850 and jaw bellows 2855 each include a plurality of bellows
formed of a cushioning material such as silicone. In various embodiments,
chin bellows 2850 and/or jaw bellows 2855 may be formed of the same
material as facial skin interface 130. Chin bellows 2850 expands and
contracts in response to up and down movement of the chin of patient 101,
such as when patient 101 opens and closes his/her mouth during speaking.
Jaw bellows 2850 is inboard of the sealing surface of facial skin
interface 130, and expands and contracts in response to up, down, and
side-to-side movement of the jaw of patient 101, such as when patient 101
opens and closes his/her mouth during speaking, yawning, or for a medical
procedure accomplished through an open front portion of patient interface
110. The expansion and contraction provided by chin bellows 2850 and/or
jaw bellows 2855 allows for some linear and/or side-to-side movement of
the mouth, chin and/or jaw of patient 101 while maintaining contact
between facial skin interface 130 and the face of patient 101. This can
increase patient comfort and decrease the need to constantly manually
adjust patient interface 101 in response to unintentional leaks caused by
movement of the jaw and/or chin of patient 101. Additionally, a caregiver
or patient may access an oral or nasal opening or region through a
removable insert 120 and jostle or move portions of patient interface 110
without causing unintentional leaks. This is because the accordion like
bellows features of chin bellows 2850 and/or jaw bellows 2855 allow for
some flexing movement such that outer portions of patient interface 110
while the facial skin contacting portions remain undisturbed or
relatively undisturbed in their seating against the facial skin of the
patient.

[0204]FIG. 29 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal 135 and a facial skin interface
130, according to an embodiment. As illustrated by enlarged detail 2901,
the skin contacting portion of facial skin interface 130 comprises a
porous material 2925 (e.g., open cell foam) which provides a plurality of
small openings and small passageways in/near its surface, due to the
porosity. When patient interface 110 is donned and coupled with
ventilator 160, pressurized fresh respiratory gas flows through porous
material 2925 in a controlled and intentional leak as illustrated by gas
flow path 2926. This controlled and intentional leak facilitates a
controlled purging of moisture by both forcing moisture out through the
pores of porous material 2925, and by evaporating moisture. This
controlled and intentional leak assists in purging moisture and thus
preventing accumulation of fluids (e.g., sweat, condensation, or the
like) and/or eliminating fluids from within facial interface 110 (the
portion which covers nose and/or mouth openings when donned) and from
between facial skin interface 130 and the facial skin of patient 101 that
is in contact with facial skin interface 130 when patient interface 110
is donned. In one embodiment, porous material 2925 may be a
removable/replaceable component which is removably coupled with facial
skin interface 130. Thus when porous material 2925 gets clogged or
exceeds a recommended service time, this replaceable component can be
replaced.

[0205] As illustrated in FIG. 29, the skin contacting portion of compliant
nose bridge seal 135 may additionally or alternatively be configured with
a similar porous material 2935 which provide small passageways and
openings in/near its surface, due to the porosity. When patient interface
110 is donned and coupled with ventilator 160, pressurized fresh
respiratory gas flows through pores of porous material 2935 in a
controlled and intentional leak as illustrated by gas flow path 2936.
This controlled and intentional leak facilitates a controlled purging of
moisture by both forcing moisture out through pores of porous material
2935, and by evaporating moisture. This controlled leak assists in
purging moisture and thus preventing accumulation of fluids (e.g., sweat,
condensation, or the like) and/or eliminating fluids from within facial
interface 110 (the portion which covers nose and/or mouth openings when
donned) and from between compliant nose bridge seal 135 and the facial
skin of patient 101 that is in contact with compliant nose bridge seal
135 when patient interface 110 is donned. In one embodiment, porous
material 2935 may be a removable/replaceable component which is removably
coupled with compliant nose bridge seal 135. Thus when porous material
2935 gets clogged or exceeds a recommended service time, this replaceable
component can be replaced.

[0206] As illustrated in FIG. 29, in one embodiment, facial skin interface
130 additionally or alternatively includes an extended chin portion 832,
which may include a chin bellows 2850 and/or may include a jaw bellows
2850.

[0207]FIG. 30 illustrates a perspective view of the skin contacting
portion of a compliant nose bridge seal 135 and a facial skin interface
130, according to an embodiment. As illustrated by enlarged detail 3001,
the skin contacting portion of facial skin interface 130 is comprises a
wicking material 3025 (e.g., a woven cloth such as cotton, wool, bamboo,
polyester micro fiber, or other known wicking materials) which provides a
surface that naturally wicks fluids and moisture. In some embodiments,
the wicking surface of facial skin interface 130 may be textured. This
wicking property assists in wicking moisture and thus preventing
accumulation of fluids (e.g., sweat, condensation, or the like) and/or
eliminating fluids from within facial interface 110 (the portion which
covers nose and/or mouth openings when donned) and from between facial
skin interface 130 and the facial skin of patient 101 that is in contact
with facial skin interface 130 when patient interface 110 is donned. In
one embodiment, wicking material 3025 may be a removable/replaceable
component which is removably coupled with facial skin interface 130. Thus
when wicking material 3025 gets clogged, saturated, or exceeds a
recommended service time; this replaceable component can be replaced. In
some embodiments, the wicking material 3024 may be porous enough to
exhibit purging properties as well as wicking properties. Arrow 3026
illustrates the direction of gas flow through a porous wicking material
3024.

[0208] As illustrated in FIG. 30, the skin contacting portion of compliant
nose bridge seal 135 may additionally or alternatively be configured with
a similar wicking material 3035 (e.g., a woven cloth such as cotton,
wool, bamboo, polyester micro fiber, or other known wicking materials)
which provides a textured surface that naturally wicks fluids and
moisture. Wicking material 3035 provides a textured wicking surface for
interfacing with nasal skin of patient 101 when patient interface 110 is
donned. This wicking property assists in wicking moisture and thus
preventing accumulation of fluids (e.g., sweat, condensation, or the
like) and/or eliminating fluids from within facial interface 110 (the
portion which covers nose and/or mouth openings when donned) and from
between compliant nose bridge seal 135 and the facial skin of patient 101
that is in contact with compliant nose bridge seal 135 when patient
interface 110 is donned. In one embodiment, wicking material 3035 may be
a removable/replaceable component which is removably coupled with
compliant nose bridge seal 135. Thus when wicking material 3035 gets
clogged, saturated, or exceeds a recommended service time; this
replaceable component can be replaced. In some embodiments, wicking
material 3034 may be porous enough to exhibit purging properties as well
as wicking properties. Arrow 3036 illustrates the direction of gas flow
through a porous wicking material 3034.

[0209] As illustrated in FIG. 30, in one embodiment, facial skin interface
130 additionally or alternatively includes an extended chin portion 832,
which may include a chin bellows 2850 and/or may include a jaw bellows
2850.

[0210] In some embodiments, all or a portion of facial skin interface 130,
compliant nose bridge seal 135, micro-grooves 2825, porous material 3925,
and/or wicking material 3025 is imbued with one or more substances which
actively soothe/protect the facial skin in one or more areas which
receive contact from a patient interface as a result of non-invasive
ventilation. Such substances may include one or more of an antibacterial
substance (e.g., tricolsan, silver, or other known substances with
antibacterial and/or antifungal properties), an emollient, and/or a
vasodilator. An imbued antibacterial can prevent/destroy a bacteria
and/or a fungus which may inhabit the environment where facial skin of a
patient contacts or is enclosed by patient interface 110. An imbued
emollient softens and moisturizes the skin, and can thus assist in
prevention of chafing, rashes, and skin necrosis caused by prolonged
contact between patient interface 110 and facial skin of patient 101. A
imbued vasodilator dilates (widens) blood vessels by relaxing smooth
muscle cells of the vessel walls, thus improving blood flow in facial
skin. Such improved blood flow can assists in preventing necrosis that
can occur if patient interface 110 causes a pressure point on facial skin
of patient 101, or can prolong the amount of time that patient interface
110 can be worn without damaging facial skin of patient 101.

[0211] In some or all embodiments, all or portions of facial skin
interface 130 may be treated with a low shear force adhesive such that a
slight tackiness (similar to that of a Post-It® note) is achieved.
This tackiness improves mask stability, thus reducing the amount of
sliding and decreasing irritation to the skin caused by constant sliding
and shifting.

Section 13

Non-Invasive Ventilation Facial Skin Protection

[0212] Referring again to FIG. 8A, a patient interface which includes a
zygomatic facial interface 831 (831-1, 831-2) is illustrate, according to
an embodiment. In one embodiment, zygomatic facial interface is an
extension of or is coupled with facial skin interface 130. In one
embodiment, first zygomatic interface portion 831-1 sealably interfaces
with facial skin covering a left zygomatic arch region of patient 101,
while second zygomatic interface portion sealably interfaces with facial
skin covering a right zygomatic arch region of patient 101. In response
to application of a securing force for securing patient interface 110 and
facial skin interface 130 over a mouth and/or nose opening of said
patient, first portion 831-1 and second portion 831-2 spreading the
securing force away from a nasal bridge of patient 101 and onto to the
left and right zygomatic arch regions of patient 101. The securing force
is supplied by a head strap system, such as or similar to head strap
system 111, which supplies the securing force in response to donning of
patient interface 110. In one embodiment, zygomatic facial interface 831
may comprise a plurality of bladders 836, which may be inflated with a
fluid or may be inflated with fresh respiratory gas supplied by
ventilator 160. In some embodiments, zygomatic facial interface 831
includes a moisture purging feature (e.g., micro-grooves 2825 and/or
porous material 3025) which contacts facial skin of patient 101 and which
allows/facilitates a controlled and intentional leak of fresh respiratory
gas between the moisture purging feature and the facial skin of patient
101. In one embodiment, zygomatic facial interface 831 includes a wicking
feature (e.g., wicking material 3025) which contacts facial skin of
patient 101 and wicks fluid from the contacted facial skin. In one
embodiment, a skin contacting region of zygomatic facial interface 831 is
imbued with at least one of an emollient, an antibacterial, and a
vasodilator. In one embodiment, a skin contacting region of zygomatic
facial interface is imbued with two or more of an emollient, an
antibacterial, and a vasodilator.

[0213] In various embodiments, a patient interface 110 which utilizes
zygomatic facial interface 831 may include extended chin portion 832
(which may further include chin bellows 2850). It is appreciated that
other features described herein may be included, in various combinations
with a patient interface 110 which includes zygomatic facial skin
interface 831. For example, in some embodiments, a patient interface 110
which utilizes zygomatic facial interface 831 may include compliant nose
bridge seal 135, corrugations, jaw bellows, tube insertion region,
microgrooves, porous material, wicking material, and nasal passage
opening features, among other features.

[0214] Although features have been illustrated and described herein as
applied to oral/nasal patient interfaces which seal about the mouth and
nose openings of a patient, it is appreciated that the features described
herein may also be applied to patient interfaces which seal only about a
mouth opening of a patient or only about a nose opening of a patient.

[0215] The foregoing descriptions of specific embodiments have been
presented for purposes of illustration and description. They are not
intended to be exhaustive or to limit the presented technology to the
precise forms disclosed, and obviously many modifications and variations
are possible in light of the above teaching. The figures and embodiments
were chosen and described in order to best explain the principles of the
presented technology and its practical application, to thereby enable
others skilled in the art to best utilize the presented technology and
various embodiments with various modifications as are suited to the
particular use contemplated. While the subject matter has been described
in particular embodiments, it should be appreciated that the subject
matter should not be construed as limited by such embodiments, but rather
construed according to the following claims.